>Did you do more then just rename the file? You will need to rename the class it was based upon, in the code behind. Or make sure there are no old references in the RESX file. But, I would just make sure you rename the file and the class in the code behind to make sure it changes.

Yes, you're right. In the Class view, I have a class named WebForm1. However, the interface doesn't allow me to change its name. Do you know how to do it?