背景图片铺不满全屏时处理：
background-size:cover; //css3 属性IE8 不支持 <!--相对路径--> filter: progid:DXImageTransform.Microsoft.AlphaImageLoader (src='/hezebus/static/image/bj.jpg', sizingMethod='scale'); //兼容IE8 <!-- filter: progid:DXImageTransform.Microsoft.AlphaImageLoader (src='D:/Java/tomcat/apache-tomcat-6.0.35/webapps/hezebus/static/image/bj.jpg', sizingMethod='scale'); //兼容IE8 -->
