I have 2 Files. One is aspx and its ascx. aspx contains Javascript which calculates count down time for exam. while timer value reaches to 00:00:00 I want to invoke an event “Submit Exam” which is in ascx file. Final Paper.aspx.cs Final Paper.aspx Exam_paper.ascx Answer Make your btnSubmit a public property of your usercontrol, so that it can be accessible