I am highly grateful to you Mr. Ramanan..
Thanks for your reply and it worked perfectly..
Thanks once again....

This Script below works perfectly in firefox but fails to execute in Internet Explorer.Kindly copy and paste the script below to see it working.What i require is if i click 'MENU1' and it is still in visible state and i click 'MENU2' or 'MENU3' then the previous open Menu i.e(MENU1) should hide its sublinks and the one clicked should display its sublinks. So conclusion is that only sublinks of one group can be viewed at a time and hiding the rest.....