really strange problem with my MS ASP.NET software

Question

Hello everybody. Maybe this is the strangest problem I've ever had with software. So I do enter the most simple function ("onclick" on the button Just to do "this.textbox1.text="asd"; "). So when I try just one and the same function in Main.aspx and in Test.aspx in the Main.aspx it just doesn't work and in the Test.aspx it works. I 'll be really gratefull to anybody who had that problem and try to help me. Thank you! Greetings: G Kalchev