select 가 배열일 경우 사용...
좀 다듬어서 function 으로 만들어 놓구 쓰면 좋겠네요
<form method="post" name="frm">
<select name="a[0]" >
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<script>
var obj = eval(document.frm['a[0]']);
obj.value=5;
</script>
</select>
<select name="a[1]" >
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<script>
var obj = eval(document.frm['a[1]']);
obj.value=4;
</script>
</select>
<select name="a[2]" >
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<script>
var obj = eval(document.frm['a[2]']);
obj.value=3;
</script>
</select>
<select name="a[3]" >
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<script>
var obj = eval(document.frm['a[3]']);
obj.value=2;
</script>
</select>
<select name="a[4]" >
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<script>
var obj = eval(document.frm['a[4]']);
obj.value=1;
</script>
</select>
</form>