Today I was working on a maintenance Web page that triggers a SQL Server stored procedure. This stored procedure can either run quite quickly, or it can take in excess of seven minutes to finish. So in order to let the user know that the process is executing in the background I added a small floating div to the page with a message encouraging patience that the code is still running and I disabled the submit button so the form could not be submitted more than once.
The floating div/submit button disabling is triggered on click of the submit button using the OnClientClick attribute. However on the page I also have some RequiredFieldValidator and RegularExpressionValidator controls.