初始化页面垂直居中

//初始化页面垂直居中
		var gDocHeight = $('.login').height();
		resizeBody();

		function resizeBody() {
			var winHeight = $(window).height();
			var heightGap = winHeight - gDocHeight;

			if(heightGap > 5) {
				$('.login').css('padding-top', heightGap / 2);
			} else {
				$('.login').css('padding-top', 0);
			}
		}
		window.onresize = function() {
			resizeBody();
		};