就是这个思路了~~~<script language="javascript">
<!--
function fncadd(v,t)
{
var o1 = document.all.s1;
var o2 = document.all.s2;
var f;
for(var i=0;i<o2.length;i++)
{
if(o2[i].text == t)
{
f='1';
alert('有重复内容,不添加!');
}
}
if(f != '1') s2.options.add(new Option(t,v));
}
//-->
</script><select name=s1 onchange="fncadd(this.value,this.options[this.selectedIndex].text);">
<option>a1
<option>a2
<option>a3
</select>
<select name=s2>
<option>b1
<option>a2
<option>b3
</select>
<!--
function fncadd(v,t)
{
var o1 = document.all.s1;
var o2 = document.all.s2;
var f;
for(var i=0;i<o2.length;i++)
{
if(o2[i].text == t)
{
f='1';
alert('有重复内容,不添加!');
}
}
if(f != '1') s2.options.add(new Option(t,v));
}
//-->
</script><select name=s1 onchange="fncadd(this.value,this.options[this.selectedIndex].text);">
<option>a1
<option>a2
<option>a3
</select>
<select name=s2>
<option>b1
<option>a2
<option>b3
</select>
比较管用