<html>
<head>
<SCRIPT LANGUAGE="JavaScript">
function moveOver() {
var boxLength = document.choiceForm.choiceBox.length;
var selectedItem = document.choiceForm.available.selectedIndex;
var selectedText = document.choiceForm.available.options[selectedItem].text;
var selectedValue = document.choiceForm.available.options[selectedItem].value;
var i;
var isNew = true;
if (boxLength != 0) {
for (i = 0; i < boxLength; i++) {
thisitem = document.choiceForm.choiceBox.options[i].text;
if (thisitem == selectedText) {
isNew = false;
break;
}
}
}
if (isNew) {
newoption = new Option(selectedText, selectedValue, false, false);
document.choiceForm.choiceBox.options[boxLength] = newoption;
}
document.choiceForm.available.selectedIndex=-1;
}
function removeMe() {
var boxLength = document.choiceForm.choiceBox.length;
arrSelected = new Array();
var count = 0;
for (i = 0; i < boxLength; i++) {
if (document.choiceForm.choiceBox.options[i].selected) {
arrSelected[count] = document.choiceForm.choiceBox.options[i].value;
}
count++;
}
var x;
for (i = 0; i < boxLength; i++) {
for (x = 0; x < arrSelected.length; x++) {
if (document.choiceForm.choiceBox.options[i].value == arrSelected[x]) {
document.choiceForm.choiceBox.options[i] = null;
}
}
boxLength = document.choiceForm.choiceBox.length;
}
}
</script>
</HEAD>
<BODY>
<center>
<form name="choiceForm">
<table border=0>
<tr>
<td valign="top" width=175>
<br>
<select name="available" style="width:150" size=10 onchange="moveOver();">
<option value=1>1
<option value=2>2
<option value=3>3
<option value=4>4
<option value=5>5
</select>
</td>
<td valign="top">
<br>
<select multiple name="choiceBox" style="width:150;" size="10">
</select>
</td>
</tr>
<tr>
<td colspan=2 height=10>
<input type="button" value="제거" onclick="removeMe();">
</td>
</tr>
</table>
</form>
</center>
출처 : http://kin.naver.com/db/detail.php?d1id=1&dir_id=10102&eid=qRFjj/3N857kDnf/QEEU/RNP2SxZiBso&qb=c2VsZWN0IG9wdGlvbiBmb3Jt
