//centering popup
function popup( pageY ){
	//request data for centering
	var pageY;
	var windowWidth = document.documentElement.clientWidth;
	var windowHeight = document.documentElement.clientHeight;
	var popupHeight = $("#popupBox").height();
	var popupWidth = $("#popupBox").width();
	//centering
	$("#popupBox").css({
		"position": "absolute",
		"top": pageY-popupHeight/2,
		"left": windowWidth/2-popupWidth/2
	});
	//only need force for IE6
	$("#backgroundPopupBox").css({
		"height": windowHeight
	});
	//loading popup with jQuery magic!
	$("#backgroundPopupBox").css({
			"opacity": "0.7"
	});
	$("#backgroundPopupBox").fadeIn("slow");
	$("#popupBox").fadeIn("slow");
}
function closePopup(){
	//disables popup only if it is enabled
	$("#backgroundPopupBox").fadeOut("slow");
	$("#popupBox").fadeOut("slow");
}