I want to update the properties (width, height) of the usercontrol inside my radwindow whenever the radwindow changes it's size. I tried using the sizechanged event, but that event fires continuously making the update very demanding on the server. How do I solve this? There should be two events; a sizechange event (that fires continuously when the left mouse button is down) and a sizechanged event that fires once the user releases the left mousebutton. Also, the left mousebutton events do not fire when resizing (alternative solution). Any other solutions/workarounds?