树型菜单的问题

[andy_lin]

function expandIt(el) {
if (!ver4) return;
if (IE4) {
whichEl = eval(el + "Child");
if (whichEl.style.display == "none") {
whichEl.style.display = "block";
}
else {
whichEl.style.display = "none";
}
}
else {
whichEl = eval("document." + el + "Child");
if (whichEl.visibility == "hide") {
whichEl.visibility = "show";
}
else {
whichEl.visibility = "hide";
}
arrange();
}
}

这断程序显示一个子菜单KB0Child，如果这个div不存在，怎么修改跳过显示

[adamcn]

直接用if (whichEl)就行了
存在是true，不存在是false

[andy_lin]

if (!whichEl) return;还是不行，说KB0Child未定义

[stroll]

if(window[el + "Child"])
alert("存在")
else
alert("没有……")

[qiushuiwuhen]

<div id=myChild>myChild</div>
<script>
function expandIt(el) {
try{whichEl = eval(el + "Child")}catch(e){return};
alert(el+":"+whichEl.innerText);
}
expandIt("KBO")
expandIt("my")
</script>