Running back ground action

I need some thi开发者_如何学编程ng like sending SMS to inactive users. If some user is inactive for 36hrs he much get a text saying you are away from this site To do this how an ASP.NET page fires the query for every 3 minutes to check for the new user's inactivity in database.

I have a code to perform the query. I need how in ASP.NET to run query for every 3 minutes without opening browser. Do ASCX file does my work? or should I use something else.

Use Timer control for this Click Here

and in page load you can send the code if your update panel has updated