function addLoadEvent(func){
	/* appends a function to the onload event */
	
	var oldonload = window.onload;
	if(typeof window.onload != 'function'){
		window.onload = func;
	}else{
		window.onload = function(){
			oldonload();
			try {
			    func();
			}
		    catch(err){            
                alert("Error in addLoadEvent:" +  err);
            }
		}
	}
}