There is no class file in the project associated with the Web Forms file 'form'. Create a new class file now?
You have created a new Web Forms page or opened an existing Web Forms page that does not yet have an associated class file.
To respond to this message
Click Yes in the dialog box to create a new class file.
- or -
Click No, and then add an existing class file to the solution or project.
See Also
Concepts
ASP.NET Web Forms Pages Overview
Other Resources
Design-Time Support for Web Forms