css 取消默认的padding

body,div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,form,fieldset,input,textarea,p,blockquote,th,td,img,u,i {list-style:none;padding:0;margin:0;}

 --透明 兼容写法

filter:alpha(opacity=90);-moz-opacity:0.9;    -khtml-opacity: 0.9;opacity: 0.9;