InfoPath Dev

Hi,

 I am trying to assign roles to a document library item from InfoPath code and have issues with it

using (SPSite site = new SPSite(http://mysite_url)) (where http://mysite_url is the site on the local machine I am coding)

it complains the site doesn't exsit (and it surely does) 

Then I was trying to wrap everying (myfunction) into  SPSecurity.RunWithElevatedPrivileges(), now I get an exception "Object reference not set to an instance of an object" on the line SPSecurity.RunWithElevatedPrivileges(myfunction),

This is so weird, does anybody know why?

Any help or advice yet?

Hey here is a hint of another version of my qestion about this error:

I am pretty much sure it's a security issue. I am
runing InfoPath 2007. Question and hint: What user identity and
application pool to run the InfoPath web form or service. How should I
know that?

I need to check the identity or impersonate an admin user to do this.

How to do impersonation in InfoPath form. I added a block of code in the infopath.exe.config in my local development machine and the web.config of the virtual directory of the stage machine, none of them works

<system.web>
  <identity impersonate="true" userName="OurDomain\OurAdminAccount" password="xxxxxxxx" />
 </system.web>

Any idea?

A even much simpler version of my question:

Is that possible to access SPSite and SPWeb object from InfoPath Code (FormCode.cs)? How?