Hi, I'm working with a SIP client called SIPCommunicator which uses Felix. I've created a new bundles adding new functionalities to the SIP Client, and I'm having some problems with the integration in felix. In the build procees I can get the jar bundles files, but when I try to run Felix I get this error: ********************************************* Welcome to Felix. [java] ================= [java] IOException in readRegistry: java.io.EOFException [java] ERROR: Error starting reference:file:sc-bundles/swing-ui.jar (org.osgi.framework.BundleException: Unresolved constraint in bundle 65: package; (&(package=org.apache.log4j.spi)(version>=0.0.0))) [java] org.osgi.framework.BundleException: Unresolved constraint in bundle 65: package; (&(package=org.apache.log4j.spi)(version>=0.0.0)) [java] at org.apache.felix.framework.Felix._resolveBundle(Felix.java:1775) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1635) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] ERROR: Error starting reference:file:sc-bundles/systray.jar (org.osgi.framework.BundleException: Activator start error in bundle [67].) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.impl.systray.SystrayActivator.getUIService(SystrayActivator.java:113) [java] at net.java.sip.communicator.impl.systray.jdic.SystrayServiceJdicImpl.<init>(SystrayServiceJdicImpl.java:126) [java] at net.java.sip.communicator.impl.systray.SystrayActivator.start(SystrayActivator.java:49) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] ERROR: Error starting reference:file:sc-bundles/icqaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [30].) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.icqaccregwizz.IcqAccRegWizzActivator.start(IcqAccRegWizzActivator.java:48) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.aimaccregwizz.AimAccRegWizzActivator.start(AimAccRegWizzActivator.java:46) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] ERROR: Error starting reference:file:sc-bundles/aimaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [31].) [java] ERROR: Error starting reference:file:sc-bundles/sipaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [32].) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.sipaccregwizz.SIPAccRegWizzActivator.start(SIPAccRegWizzActivator.java:56) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] ERROR: Error starting reference:file:sc-bundles/jabberaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [33].) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.jabberaccregwizz.JabberAccRegWizzActivator.start(JabberAccRegWizzActivator.java:57) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] ERROR: Error starting reference:file:sc-bundles/googletalkaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [34].) [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.googletalkaccregwizz.GoogleTalkAccRegWizzActivator.start(GoogleTalkAccRegWizzActivator.java:45) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] ERROR: Error starting reference:file:sc-bundles/msnaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [35].) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.msnaccregwizz.MsnAccRegWizzActivator.start(MsnAccRegWizzActivator.java:53) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] ERROR: Error starting reference:file:sc-bundles/yahooaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [36].) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.yahooaccregwizz.YahooAccRegWizzActivator.start(YahooAccRegWizzActivator.java:53) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] ERROR: Error starting reference:file:sc-bundles/gibberishaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [37].) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.gibberishaccregwizz.GibberishAccRegWizzActivator.start(GibberishAccRegWizzActivator.java:58) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] ERROR: Error starting reference:file:sc-bundles/sshaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [38].) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.sshaccregwizz.SSHAccRegWizzActivator.start(SSHAccRegWizzActivator.java:65) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] ERROR: Error starting reference:file:sc-bundles/rssaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [40].) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.rssaccregwizz.RssAccRegWizzActivator.start(RssAccRegWizzActivator.java:53) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] ERROR: Error starting reference:file:sc-bundles/zeroconfaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [41].) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.zeroconfaccregwizz.ZeroconfAccRegWizzActivator.start(ZeroconfAccRegWizzActivator.java:54) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] ERROR: Error starting reference:file:sc-bundles/ircaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [42].) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.ircaccregwizz.IrcAccRegWizzActivator.start(IrcAccRegWizzActivator.java:48) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] ERROR: Error starting reference:file:sc-bundles/chatalerter.jar (org.osgi.framework.BundleException: Activator start error in bundle [47].) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.chatalerter.ChatAlerterActivator.start(ChatAlerterActivator.java:73) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] ERROR: Error starting reference:file:sc-bundles/generalconfig.jar (org.osgi.framework.BundleException: Activator start error in bundle [50].) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.generalconfig.GeneralConfigPluginActivator.start(GeneralConfigPluginActivator.java:32) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) [java] java.lang.NullPointerException: Specified service reference cannot be null. [java] at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:320) [java] at net.java.sip.communicator.plugin.dictaccregwizz.DictAccRegWizzActivator.start(DictAccRegWizzActivator.java:52) [java] at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:589) [java] at org.apache.felix.framework.Felix._startBundle(Felix.java:1654) [java] at org.apache.felix.framework.Felix.startBundle(Felix.java:1578) [java] at org.apache.felix.framework.Felix.setFrameworkStartLevel(Felix.java:1172) [java] ERROR: Error starting reference:file:sc-bundles/dictaccregwizz.jar (org.osgi.framework.BundleException: Activator start error in bundle [51].) [java] at org.apache.felix.framework.StartLevelImpl.run(StartLevelImpl.java:265) [java] at java.lang.Thread.run(Thread.java:619) *************************************************************** ...and my config.properties file called felix.client.run.properties, is the following: ****************************************************** # # Framework config properties. # org.osgi.framework.system.packages.extra= org.osgi.framework; version=1.3.0, \ javax.swing; \ javax.swing.event; \ javax.swing.table; \ javax.swing.text; \ javax.swing.text.html; \ javax.accessibility; \ javax.swing.plaf; \ javax.swing.plaf.metal; \ javax.swing.plaf.basic; \ javax.imageio; \ javax.swing.tree; \ javax.swing.undo; \ javax.swing.event; \ javax.swing.border; \ javax.swing.filechooser; \ org.w3c.dom; \ org.xml.sax; \ org.xml.sax.ext; \ javax.xml.parsers;\ org.apache.xml.serialize; \ javax.xml.transform; \ javax.xml.transform.dom; \ javax.xml.transform.stream; \ sun.security.action; \ sun.misc; \ javax.net; \ javax.net.ssl; \ javax.naming; \ javax.naming.directory; \ javax.sound;\ javax.sound.sampled; \ org.jdesktop.jdic.tray; \ org.jdesktop.jdic.desktop; \ com.apple.cocoa.application; \ com.apple.cocoa.foundation; \ com.apple.eawt; \ com.apple.eio; \ quicktime; \ quicktime.std.sg; \ quicktime.qd; \ quicktime.util; \ quicktime.std.image; \ org.xml.sax.helpers; \ javax.crypto; \ javax.crypto.spec; \ javax.crypto.interfaces; \ net.java.sip.communicator.util.launchutils; \ org.bouncycastle.jce.provider; \ org.bouncycastle.crypto.digests; \ org.bouncycastle.crypto.macs; \ org.bouncycastle.crypto.params; \ org.bouncycastle.crypto.engines;
felix.auto.start.10= \ reference:file:lib/bundle/org.apache.felix.bundlerepository-1.0.0.jar # file:lib/bundle/shell.jar \ # file:lib/bundle/servicebinder.jar \ # file:lib/bundle/tablelayout.jar felix.auto.start.20= \ reference:file:sc-bundles/util.jar \ reference:file:lib/bundle/log4j.jar felix.auto.start.30= \ reference:file:sc-bundles/fileaccess.jar felix.auto.start.40= \ reference:file:sc-bundles/configuration.jar \ reference:file:sc-bundles/resourcemanager.jar \ reference:file:sc-bundles/jfontchooserlib.jar \ reference:file:sc-bundles/browserlauncher.jar felix.auto.start.42= \ reference:file:sc-bundles/defaultresources.jar felix.auto.start.45= \ reference:file:sc-bundles/ui-service.jar \ reference:file:sc-bundles/argdelegation-service.jar \ reference:file:sc-bundles/version.jar \ reference:file:sc-bundles/version-impl.jar \ reference:file:sc-bundles/branding.jar felix.auto.start.49= \ reference:file:sc-bundles/zrtp4j.jar \ reference:file:sc-bundles/protocol.jar #the contact list service depends on protocol.jar #some protocol implementations however depend on the contact list #so make sure load the procotol service first, the contact list next # and the implementations only after felix.auto.start.50= \ reference:file:sc-bundles/contactlist.jar felix.auto.start.52= \ reference:file:sc-bundles/media.jar \ reference:file:sc-bundles/protocol-icq.jar \ reference:file:sc-bundles/protocol-sip.jar \ reference:file:sc-bundles/smacklib.jar \ reference:file:sc-bundles/protocol-jabber.jar \ reference:file:sc-bundles/protocol-msn.jar \ reference:file:sc-bundles/protocol-yahoo.jar \ reference:file:sc-bundles/protocol-gibberish.jar \ reference:file:sc-bundles/protocol-ssh.jar \ reference:file:sc-bundles/netaddr.jar \ reference:file:sc-bundles/protocol-zeroconf.jar \ reference:file:sc-bundles/protocol-irc.jar \ reference:file:sc-bundles/protocol-dict.jar felix.auto.start.55= \ reference:file:sc-bundles/meta-cl.jar felix.auto.start.56= \ reference:file:sc-bundles/protocol-rss.jar felix.auto.start.60= \ reference:file:sc-bundles/history.jar \ reference:file:sc-bundles/msghistory.jar \ reference:file:sc-bundles/callhistory.jar \ reference:file:sc-bundles/audionotifier.jar \ reference:file:sc-bundles/keybindings.jar \ reference:file:sc-bundles/notification.jar felix.auto.start.66= \ reference:file:sc-bundles/swing-ui.jar \ reference:file:sc-bundles/updatechecker.jar \ reference:file:sc-bundles/systray.jar felix.auto.start.67= \ reference:file:sc-bundles/pluginmanager.jar \ reference:file:sc-bundles/whiteboard.jar \ reference:file:sc-bundles/icqaccregwizz.jar \ reference:file:sc-bundles/aimaccregwizz.jar \ reference:file:sc-bundles/sipaccregwizz.jar \ reference:file:sc-bundles/jabberaccregwizz.jar \ reference:file:sc-bundles/googletalkaccregwizz.jar \ reference:file:sc-bundles/msnaccregwizz.jar \ reference:file:sc-bundles/yahooaccregwizz.jar \ reference:file:sc-bundles/gibberishaccregwizz.jar \ reference:file:sc-bundles/sshaccregwizz.jar \ reference:file:sc-bundles/callhistoryform.jar \ reference:file:sc-bundles/rssaccregwizz.jar \ reference:file:sc-bundles/zeroconfaccregwizz.jar \ reference:file:sc-bundles/ircaccregwizz.jar \ reference:file:sc-bundles/contacteventhandler.jar \ reference:file:sc-bundles/notificationconfig.jar \ reference:file:sc-bundles/contactinfo.jar \ reference:file:sc-bundles/accountinfo.jar \ reference:file:sc-bundles/chatalerter.jar \ reference:file:sc-bundles/autoaway.jar \ reference:file:sc-bundles/keybindingChooser.jar \ reference:file:sc-bundles/generalconfig.jar \ reference:file:sc-bundles/dictaccregwizz.jar #level 68 is for profiler, don't use it or change the build.xml file accordingly felix.auto.start.70= \ reference:file:sc-bundles/simpleaccreg.jar felix.auto.start.75= \ reference:file:sc-bundles/argdelegation.jar felix.auto.start.80= \ reference:file:sc-bundles/shutdown.jar felix.auto.start.95=\ reference:file:sc-bundles/wsdl4j-151-axis.jar \ reference:file:sc-bundles/axis-axis.jar \ reference:file:sc-bundles/axis-ant-axis.jar \ reference:file:sc-bundles/commons-discovery-axis.jar \ reference:file:sc-bundles/commons-logging-axis.jar \ reference:file:sc-bundles/jaxrpc-axis.jar \ reference:file:sc-bundles/saaj-axis.jar \ reference:file:sc-bundles/virtualwaitingroomEnabler.jar \ reference:file:sc-bundles/esbConfigurationEnabler.jar \ reference:file:sc-bundles/groupmanagerEnabler.jar \ reference:file:sc-bundles/synchronizedimagesharingEnabler.jar \ reference:file:sc-bundles/videconferenceEnabler.jar \ reference:file:sc-bundles/virtualwaitingqueueEnabler.jar \ # Uncomment the following lines if you want to run the architect viewer # bundle. oscar.auto.start.100= \ file:lib/bundle/architectureviewer1.1.jar #Specify the directory where oscar should deploy its bundles org.osgi.framework.storage=${net.java.sip.communicator.SC_HOME_DIR_LOCATION}/${net.java.sip.communicator.SC_HOME_DIR_NAME}/sip-communicator.bin org.osgi.framework.startlevel=100 felix.startlevel.framework=100 felix.startlevel.bundle=100 # # Bundle config properties. # #org.osgi.service.http.port=8080 #osgi.shell.telnet=on #oscar.repository.url=file:/home/rickhall/projects/noscar/repository.xml oscar.embedded.execution=false ************************************************************************************************ What is happening?? I dont know anything to do. I don't understand the meaning of numbers in "felix.auto.start.20" for example. I think that this is the problem's source. Where can I find a tutorial or an explanation of this Thanks a lot Regards. Pedro