Timer stop

Question

I use different panels in a single web page in that panels i give code for different games and video application in that if i m going to select a single panel means the current selected panel is automatically minimized and the selected panel gets maximized, in one of my panel i use timer, i have the doubt is there any option to pause the timer while the window is minimized and then it will start counting when the window is maximized. and let me know where i give that coding in clear.Hope the reply will be useful.its very urgent.
Thanks in advance.