In VS2008, I go to File/New/Project, select ASP.NET Web Application and create a new project.
If I right-click on the newly created project, there is a menu item to Convert to Web Application.
I thought I just picked a Web Application. What exactly does the Convert to Web Application menu item do?
It will generate .designer file with controls from aspx/ascx file. If you have e.g. in you page control
in designer file it generates member
if you haven’t this .designer file you cannot use controls from aspx page in code behind.