//centering popup  
function centerPopup_sisu(){  
//request data for centering  
var windowWidth_sisu = document.documentElement.clientWidth;  
var windowHeight_sisu = document.documentElement.clientHeight;  
var popupHeight_sisu = $("#popup_sisu").height();  
var popupWidth_sisu = $("#popup_sisu").width();  
//centering  
$("#popup_sisu").css({  
"position": "absolute",  
"top": windowHeight_sisu/2-popupHeight_sisu/2,  
"left": "508px"  
});  
//only need force for IE6  
  
$("#popup_background").css({  
"height": windowHeight_sisu  
});  
  
}  
	$(document).ready(function() {
  		$('popup_sisu').hide();
		$('popup_background').hide();

		$('a#show_popup_sisu').click(function(){
		centerPopup_sisu();
		$('#popup_sisu').fadeIn('slow');
		$('#popup_background').fadeIn('slow');
		});
		
		$('a#close_popup_sisu').click(function(){
		centerPopup_sisu();
		$('#popup_sisu').fadeOut('slow');
		$('#popup_background').fadeOut('slow');
		});
		
		$("#popup_background").click(function(){  
		$('#popup_sisu').fadeOut('slow');
		$('#popup_background').fadeOut('slow');  
		});
		
		$(document).keypress(function(e){  
		if(e.keyCode==27){  
		$('#popup_sisu').fadeOut('slow');
		$('#popup_background').fadeOut('slow'); 
		}  
		});  
		
	});