ถามเรื่อง error "Message: Object expected" ของ javascript หน่อยครับ

// JavaScript Document
$(document).ready(function () {
		//id is the ID for the DIV you want to display it as modal window
		var id = $('#dialog3');
	
		//Get the screen height and width
		var maskHeight = $(document).height();
		var maskWidth = $(window).width();
	
		//Set heigth and width to mask to fill up the whole screen
		$('#mask').css({'width':maskWidth,'height':maskHeight});
		
		//transition effect		
		$('#mask').fadeIn(1000);	
		$('#mask').fadeTo("slow",0.8);	
	
		//Get the window height and width
		var winH = $(window).height();
		var winW = $(window).width();
              
		//Set the popup window to center
		$(id).css('top',  winH/2-$(id).height()/2);
		$(id).css('left', winW/2-$(id).width()/2);
	
		//transition effect
		$(id).fadeIn(2000); 
		
		//if mask is clicked
		$('#mask').click(function () {
			$(this).hide();
			$('.window').hide();
		});			
				
launchWindow(id);
});