css background-size 属性 兼容ie8 ie7 方案

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　　将以上 代码保存为 backgroundsize.min.htc

　　在background-size所在class中加入

-ms-behavior: url(css/backgroundsize.min.htc);
behavior: url(css/backgroundsize.min.htc);

　　

参考 ：http://www.dowebok.com/139.html