请教selec标签在火狐浏览器下兼容的问题

select标签在火狐浏览器下出现了这种情况请大神指教代码如下：select {background:url(../images/index/index_16.png) no-repeat top center; width:128px; height:25px;margin: 0; padding:0;border:none;*border:0;outline:none;display: inline-block;-webkit-appearance:none;-moz-appearance:none;appearance:none;*appearance:none;cursor:pointer;}option{width:128px;height:25px;margin: 0; padding:0; -webkit-width:128px; -webkit-height:25px; -moz-width:128px; -moz-height:25px;cursor:pointer;outline:none;display:block; overflow:hidden; -webkit-appearance:none;-moz-appearance:none;appearance:none;}