$(document).ready(function() {	

	//select all the a tag with name equal to modal
	$('a[name=modal]').click(function(e) {
		//Cancel the link behavior
		e.preventDefault();
		//Get the A tag
		var id = $(this).attr('href');
	
		//Get the screen height and width
		var maskHeight = $(document).height();
		var maskWidth = $(window).width();
		
		//var maskWidth = $('#wrapper').width();
	
		//Set height and width to mask to fill up the whole screen
		$('#mask').css({'width':maskWidth,'height':maskHeight});
		
		//transition effect		
		$('#mask').fadeIn("fast");	
		$('#mask').fadeTo("fast",0.8);	
	
		//Get the window height and width
		//var winH = $(window).height() - $('#mainmenubar').height() - $('#header').height();
		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);
		
		$(id).center();

	
		//transition effect
		$(id).fadeIn("fast"); 
	
	});
	
	//if close button is clicked
	$('.window .close').click(function (e) {
		//Cancel the link behavior
		e.preventDefault();
		$('#mask, .window').hide();
	});		
	
	//if mask is clicked
	$('#mask').click(function () {
		$(this).hide();
		$('.window').hide();
	});			
	
});

jQuery.fn.center = function () {
    this.css("position","absolute");
    this.css("top", ( $(window).height() - this.height() ) / 2+$(window).scrollTop() + "px");
    this.css("left", ( $(window).width() - this.width() ) / 2+$(window).scrollLeft() + "px");
    return this;
}