clickTag_bn.addEventListener(MouseEvent.CLICK, onMouseClick);
function onMouseClick(event:MouseEvent):void {
            navigateToURL(new URLRequest(clickTag), “_blank”); 
}

1. Create button that covers the entire ad.
2. Create an instance of the button on the main timeline and name it "clickTag_bn" in the properties palette.
3. On a new layer add ActionScript to the timeline as follows:

clickTag using ActionScript 3

actionscript, flash, 3

ActionScript 3