Set Tooltip width and height
<?xml version="1.0"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"> <mx:Script> import mx.managers.ToolTipManager; import mx.controls.ToolTip; public var myTip:ToolTip; private function createBigTip():void { var s:String = "tooltip"; myTip = ToolTipManager.createToolTip(s,10,10) as ToolTip; myTip.setStyle("backgroundColor",0xFF0000); myTip.width = 200; myTip.height = 200; } private function destroyBigTip():void { ToolTipManager.destroyToolTip(myTip); } </mx:Script> <mx:Panel rollOver="createBigTip()" rollOut="destroyBigTip()"> <mx:Button label="OK" toolTip="this is a test"/> </mx:Panel> </mx:Application>