SSIS Webservice Task : SOAP HEADER REQUIRED

Hi

I would like to extract some data in using a webservice task from SSIS 2008 R2 from a httpConnection and a wsdl file... Until now No Pb, I see the service and the suggested methods...

Then When i run the task a pretty error message indicates "SOAP HEADER REQUIRED" !

Where could i fill in the necessary GUID, security key, ID... in the header ?

Shall i write a script before in a script task ? Has Anyone got an example ?

Please help :-) ?

Gilles