/* *  * @function: 对一个元素实现水平和垂直居中显示,当浏览器窗口改变大小的也能实现完全居中显示 * @param: obj为jquery对象 *  */function completelyShowCenter(obj){	$(window).resize(function(){		obj.css({			position:'absolute',			left:($(window).width()-obj.outerWidth())/2,			top:($(window).height()-obj.outerHeight())/2+$(document).scrollTop(),		});	});	$(window).resize();}