这个怎么做？

Question

<script>
function test(n)
{
var a = document.formname
if(n=="1")
{
a.input1.style.visibility="visible";
a.input2.style.visibility="visible";
a.input3.style.visibility="hidden";
a.input4.style.visibility="hidden";
a.input5.style.visibility="hidden";
a.input6.style.visibility="hidden";
}
if(n=="2")
{
a.input1.style.visibility="visible";
a.input2.style.visibility="visible";
a.input3.style.visibility="visible";
a.input4.style.visibility="visible";
a.input5.style.visibility="hidden";
a.input6.style.visibility="hidden";
}
if(n=="3")
{
a.input1.style.visibility="visible";
a.input2.style.visibility="visible";
a.input3.style.visibility="visible";
a.input4.style.visibility="visible";
a.input5.style.visibility="visible";
a.input6.style.visibility="visible";
}
}
</script>
<table>
<form name=formname>
<tr>
<td>
<select onchange="test(this.options[this.selectedIndex].value)">
<option value="1">2</option>
<option value="2">4</option>
<option value="3">6</option>
</select>
</td>
<td>
<input name=input1 style="visibility:visible"><input name=input2><input name=input3 style="visibility:hidden"><br>
<input name=input4 style="visibility:hidden"><input name=input5 style="visibility:hidden"><input name=input6 style="visibility:hidden">
</td>
</tr>
</form>
</table>

Answer 1

那用innerHTML插入行不行或者用insertInput,试试吧