Using nutch-site.xml to give parameters to plugins

[Danicela nutch]

Hi,

 I want to set properties in nutch-site.xml that I can use in a plugin after.

 For exemple, I would want to have var = 10 in this file, and then retrieve 
this value in the java code of a plugin.

 But I don't know the syntax in the xml and what class & method to use in the 
plugin for that.

 Can someone give me the rules / redirect me to a tutorial ?

 Thanks.