怎样用数组向select（下拉框）里添加item？

[ssh78]

下面是我写的，怎么不行呢？
<script language="JavaScript">
function change()
{
sel = document.getElementById('select2')

switch(document.all.select1.selectedIndex)
{
case 3: var classArray = new Array("('选项1')","('选项2')","('选项3')","('选项4)");
default:var classArray = new Array("");
}
for (var i=0;i+1;i<classArray.length-1)
{
sel.add(classArray[i]);
}
}
</script>

[awaysrain]

var oOption = document.createElement('OPTION');
oOption.text = sName;
oOption.value = sValue;
form1.select1.options.add(oOption);

[meizz]

<table border=0 cellpadding=0 cellspacing=0><form name=meizz>
<tr><td>
<select id=list1 size=8 ondblclick="moveOption(this, this.form.list2)">
<option value=A>aaaaaaaaaa
<option value=B>bbbbbbbbbb
<option value=C>cccccccccc
<option value=D>dddddddddd
<option value=E>eeeeeeeeee
<option value=F>ffffffffff
<option value=G>gggggggggg
<option value=H>hhhhhhhhhh
</select></td>
<td width=40 align=center>
<input name=add type=button value=">>>" onclick="moveOption(this.form.list1, this.form.list2)"><br><br>
<input name=sub type=button value="<<<" onclick="moveOption(this.form.list2, this.form.list1)">
</td><td>
<select id=list2 size=8 ondblclick="moveOption(this, this.form.list1)">
</select>
</td></tr></form>
</table>

<script language="JavaScript"><!--
function moveOption(e1, e2){
try{
var e = e1.options[e1.selectedIndex];
e2.options.add(new Option(e.text, e.value));
e1.options.remove(e1.selectedIndex);
} catch(e){}
}
//--></script>

[fason]

<select name="demo">
</select>
<script language="JavaScript">
<!--
var arr=["hehe","heheeh","fason"]
with(demo)
for(i=0;i<arr.length;i++)options[length]=new Option(arr[i],arr[i])
//-->
</script>

[ssh78]

改成了这样，但是不知道为什么switch语句总是默认ClassArray=("nihao","您好");
<script language="JavaScript">
function change()
{
sel = document.getElementById('select2');
switch(document.all.select1.selectedIndex)
{ case 3: var classArray = new Array("('选项1')","('选项2')","('选项3')","('选项4)");


default:var classArray = new Array("nihao","您好");

}
with (sel)
for (var i=0;i<classArray.length;i++)
{
options[length]=new Option(classArray[i],classArray[i])
}
}
</script>

[ssh78]

up

[cloudchen]

http://www.sayee.com/cloudchen/js/select.htm

[ssh78]

不行啊，他老是默认switch语句最后一句构成的数组。