Regenerate the .designer files for aspx/ascx files in Visual Studio

Sometime you might get trouble accessing your ASP.NET controls from code behind and wondering for hours to know the reason. I have also been to similar situation and I got lucky to solve it with few minutes of reasearch. If you open the .aspx file and switch between design view and html view and back it will prompt VS to check the controls and add any that are missing to the designer file.