if( $("#debaak").length > 0 )
After discussing this subject we found the following solutions. JQuery returns an object, with the get function it is possible to get any element in the jQuery object returned by the jQuery selector
flashMovie = document.getElementById("debaak");
Below you can find the necessary code for flash.
public function Main()
private function callJS(msg)
//called from js
trace('call from js:' + msg)