Control Popup from leaving browser bounds.

I have a popup which i show on mouse down. Now i can press near the edges of the browser window or the screen and this popup shows, but it popus up with a big fraction of it out of the bowser window bounds or say screen blounds.
I would like to control this so that if i click near the edges, the popup is offset backwards relative to the edge and the mouse position.
I have looked every where but failed to achieve this. Any one has an idea?

You would need to do this via java script as silverlight does not interact with the browser!

Eh, whats with the links?

Thanks DeanMc. Though i am now meant to use it with my SL applications, I hadly ever use javascript. Last time i used it was 2003. May you share a small example with me.

Im not "up" on Java Script myself, you would be best to ask in the Javascript section of the forum.