Disable a button after click (Asp.Net)

To disable a button after click, to avoid that a user re-click on it before the completion of the operation, we have tu use javascript.

The problem is that the disable javascript function remove the postback ability of the button.

To bypass this problem, we can use the following code, writing it into Page Load event:

Me.btn.Attributes("onclick") = "this.disabled = true; " & Page.GetPostBackEventReference(btnSub).ToString

Into this code, btn is the id of the button and btnSub is the routine that normally handles btn.Click event