function blackscreen() {
	$('#screen').css({"display": "block", opacity: 0.8, "width":$(document).width(),"height":$(document).height()});
	$('body').css({"overflow-x":"hidden"});
	$('#box').css({"display": "block"}).click(function(){$(this).css("display", "none");$('body').css("overflow", "auto");$('#screen').css("display", "none")});
}