Lead to Opportunity Conversion

I am trying to convert a lead directly into an opportunity. And I want the ‘create opportunity’ page to appear directly as i click on the ‘convert lead’ button in the drop down(in leads) . I tried modifying the modules/leads/metadata/convertdefs.php file. But the chanegs are not reflected.
Can you please tell the files which I need to modify in order make the above changes.

When i changed the file to be like this : http://screencast.com/t/7jZygLqLqmh

the create opportunities is now expaneded… : http://screencast.com/t/MXYJd5bm2DZ is this what you mean?