[CODE]<script>
function c_ss(va){
var i,num,op
num=document.form1.ss.length
for(i=0;i<num;i++){
op=document.form1.ss.options[i]
if(op.value==va) op.selected=true;
}
}
</script>
<form name="form1"><select name=ss>
<option value=1>111</option>
<option value=2>222</option>
<option value=3>333</option>
<option value=4>444</option>
</select>
<input type=button value=选择1 onclick="c_ss(1)">
<input type=button value=选择2 onclick="c_ss(2)">
<input type=button value=选择3 onclick="c_ss(3)">
<input type=button value=选择4 onclick="c_ss(4)">
</form>
[/CODE]