import mx.managers.CursorManager;
[Embed(source="a.png")]
private var busyCursorSymbol:Class;
private var cursorId:Number = 0;
private function initImage():void
{
myImage.source = "http://yourserver.com/logo.jpg?v=0";
cursorId = CursorManager.setCursor(busyCursorSymbol);
}
private function loadComplete():void
{
CursorManager.removeCursor(cursorId);
}