火狐下 img热点点击的边框不出现

Question

以下代码直接复制就能运营，已经兼容IE各版本和chrome浏览器，但是火狐浏览器仍然不兼容，请高手赐教

img{ outline:none; <!--移除超链的虚线框 IE9,IE8,IE6有用--> }

<img name="Dec_jhs" src="images/Dec_jhs.jpg" width="700" height="57" border="0" id="Dec_jhs" usemap="#m_Dec_jhs" alt="" hidefocus="true" /><!--火狐中仍然不生效 hidefocus="true"-->
<map name="m_Dec_jhs" id="m_Dec_jhs">
    <area shape="rect" coords="328,0,700,57" href="http://www.sina.com" target="_blank" alt="" onFocus="this.blur();"  /><!--移除超链的虚线框 chrome有用 onFocus="this.blur();-->
    <area shape="rect" coords="0,0,328,57" href="http://www.baidu.com" target="_blank" alt="" onFocus="this.blur();"  /><!--移除超链的虚线框 chrome有用 onFocus="this.blur();-->
</map>