$(document).ready(function() {	

	var id = "#dialog";

	//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 close button is clicked
	$('.window .close').click(function (e) {
		//Cancel the link behavior
		e.preventDefault();
		
		$('#mask').hide();
		$('.window').hide();
	});		
	
	//if mask is clicked
	$('#mask').click(function () {
		$(this).hide();
		$('.window').hide();
	});			
	
});