兼容ie的background-size: cover;

.bg{

    background: url() no-repeat;

    background-size:cover;

    filter: progid:DXImageTransform.Microsoft.AlphaImageLoader( src='../image/bg.jpg', sizingMethod='scale');

    -ms-filter: "progid:DXImageTransform.Microsoft.AlphaImageLoader( src='../image/bg.jpg', sizingMethod='scale')";

}