导航子菜单下拉隐藏====JS

<script type=text/javascript>
function menuFix() {
var sfEls = document.getElementById("nav").getElementsByTagName("li");
for (var i=0; i<sfEls.length; i++) {
sfEls[i].onmouseover=function() {
this.className+=(this.className.length>0? " ": "") + "sfhover";}
sfEls[i].onMouseDown=function() {
this.className+=(this.className.length>0? " ": "") + "sfhover";}
sfEls[i].onMouseUp=function() {
this.className+=(this.className.length>0? " ": "") + "sfhover";}
sfEls[i].onmouseout=function() {
this.className=this.className.replace(/sfhover/ig,"");}}}
//replace(/sfhover/ig,"")这个函数的意思就是把第二个参数替换第一个参数
//第二个参数是个空 替换之后sfhover 就被替换成空了
$(document).ready(menuFix);
</script>



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