File export not working in Update Panel

I am trying to export a file upon button click event. The structure of my app is like this.

UpdatePanel TabContainer Tab1 UserControl (Button is in UserControl) Tab1 TabContainer

I tried setting PostbackTrigger but it says control no开发者_如何学编程t found exception.

Thanks in Advance

In your Page Load try using:

ScriptManager.RegisterPostbackControl(YourControl);