Jquery stopwatch timer pausing when browser is minimized or is not in focus

Jquery stopwatch timer pausing when browser is minimized or is not in focus

Hello experts, I am using jquery timer for an online examination web application. The timer runs very well, but when the examinee minimizes the browser or opens another tab and works sometime on the tab...the timer seems to pause in the examination page. I Can't seem to find out the problem behind this issue...this problem occurs in all the major browsers...chrome,firefox, IE..