Well pooja i am using Silverlight 2 beta 2 and mainly using c#.....
I am not too sure but this would help you..Have you tried using AddEventListener ?
If "yourCanvas" is the new canvas object created on the fly then
yourCanvas.addEventListener("MouseLeftButtonDown", "canvasClicked");
function canvasClicked(sender, args)
{
Your Code Goes HERE;
}
This link might help you http://dotnet.sys-con.com/node/463961
Hope this helps...Kindly MARK AS ANSWER if it does.