We've had the same problem, Michael Pelletier addressed this question in a previous post, Check out: http://www.egroups.com/message/zope/29589?&start=29498 To summarize, 'Zope doesn't like it if there is no html tags before the DTML begins.' To fix our problem, we simply make sure that a html comment as the first line in every page, through the standard_html_header. Hope this helps, Mark ----------- [EMAIL PROTECTED] www.kaivo.com > > --- In [EMAIL PROTECTED], Richard Moon <[EMAIL PROTECTED]> wrote: > Marcel, you're English is fine (better than my Italian). > > I think you are near to the answer. > > My dtml method 'dtml_main' has this kind of logic > > <dtml-if something> > <dtml-var a_dtml_method> > <dtml-else> > <dtml-var another_dtml_method> > </dtml-if> > > I had standard_html_header (which has an html header) in each of the > 'inner' methods, but not in the 'dtml_main' method. So I took > standard_html_header out of 'a_dtml_method' and 'another_dtml_method' > and > put it in the 'dtml_main' method. No Invalid Header problems now. I > don't > know why that should make a difference but it seems to. > > Thanks for your help > > Richard > > > I found that the main dtml-method had no standard-header (so no html > header) but the methods which it was rendering > > At 15:01 23/06/00 +0200, you wrote: > > > > > Does anyone know what an Error Type: Value Error, Error > Value:Invalid > > > Header (0) error represents ? > > > > > > It's interesting in the way it shows itself up. I added a > <dtml-var > > > a_dtml_method> to a dtml method and it generates this error. This > > <dtml-var > > > a_dtml_method> is nested inside a <dtml-if> and would definitely > not be > > > rendered the first time the 'calling' dtml-method is rendered. > > > > > > I took out the <dtml-var a_dtml_method> and I still got the same > error. > > > > > > I put a <dtml-var REQUEST> as the first line of the 'calling' > method and > > > everything then renders correctly with no error. Even the > <dtml-var > > > a_dtml_method> renders correctly when it should do so. > > > > > > Any ideas, suggestions ? > > > > > > >This is very strange. > >I had have the some problem. > >I have seen that if the Zope generate a lot of empty lines at the > begining > >I receive this error. > > > >the idea is to dont have too many empty lines at the begining of the > output, > >(I have no idea how many) > > > >try to write something at the begining of the output doc. > >I use someting like "Content-type:...." > > > >PM > >PS: My English is not so good, > >maybe you dont understood what I want to say > > > > > > > >_______________________________________________ > >Zope maillist - [EMAIL PROTECTED] > >http://lists.zope.org/mailman/listinfo/zope > >** No cross posts or HTML encoding! ** > >(Related lists - > > http://lists.zope.org/mailman/listinfo/zope-announce > > http://lists.zope.org/mailman/listinfo/zope-dev ) > > > Richard Moon > [EMAIL PROTECTED] > > > > _______________________________________________ > Zope maillist - [EMAIL PROTECTED] > http://lists.zope.org/mailman/listinfo/zope > ** No cross posts or HTML encoding! ** > (Related lists - > http://lists.zope.org/mailman/listinfo/zope-announce > http://lists.zope.org/mailman/listinfo/zope-dev ) > --- End forwarded message --- > > _______________________________________________ Zope maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope-dev )