var popupStatus = 0; 
	
function loadPopup(){  
	if(popupStatus==0){  
		$("#backgroundPopup").css({"opacity": "0.7"});  
		$("#backgroundPopup").fadeIn("slow");  
		$("#popup_div").fadeIn("slow");  
		popupStatus = 1;  
	}  
}

function disablePopup(){  
	if(popupStatus==1){  
		$("#backgroundPopup").fadeOut("slow");  
		$("#popup_div").fadeOut("slow");  
		popupStatus = 0;  
	}  
}

//centering popup
function centerPopup(){
	//request data for centering
	var windowWidth = document.documentElement.clientWidth;
	var windowHeight = document.documentElement.clientHeight;

	var popupHeight = $("#popup_div").height();
	var popupWidth = $("#popup_div").width();
	//centering
	$("#popup_div").css({
	"position": "absolute",
	"top": windowHeight/2-popupHeight/2,
	"left": windowWidth/2-popupWidth/2
	});
	//only need force for IE6



}