有二个列表框，可多选。如何实现：在其中一个列表中选取多项移到另一个列表中，两者实现双向选取??
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<html><head>
<script language="javascript">
function moveOption(oFromList, oToList, bAll)
{
var nFromLen = oFromList.options.length;
var nToLen = oToList.options.length;
var i = 0;
while (nFromLen > 0)
{
if (oFromList.options[i].selected ¦ ¦ bAll)
{
oToList[nToLen++] = new Option(oFromList.options[i].text, oFromList.options[i].value);
oFromList.options[i] = null;
}
else
i++;
nFromLen--;
}
sortOption(oToList);
}
function compare(a,b)
{
if (a.text < b.text)
return -1;
else if (a.text > b.text)
return 1;
return 0;
}
function sortOption(oList)
{
if (oList.options.length > 1)
{
var optionList = new Array();
for (var i=0; i < oList.options.length; i++)
optionList.push(oList.options[i]);
optionList.sort(compare);
oList.length = 0;
for (var i=0; i < optionList.length; i++)
oList.options[i] = optionList[i];
}
}
</script>
</head><body>
<form name="form1">
<table>
<tr>
<td>
<select name="leftlist" multiple size="4">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
</select>
</td>
<td>
<input type="button" value="<<" onclick="javascript:moveOption(rightlist, leftlist,true)"><br>
<input type="button" value="<" onclick="javascript:moveOption(rightlist, leftlist,false)"><br>
<input type="button" value=">" onclick="javascript:moveOption(leftlist, rightlist,false)"><br>
<input type="button" value=">>" onclick="javascript:moveOption(leftlist, rightlist,true)">
</td>
<td>
<select name="rightlist" multiple size="4">
</select>
</td>
</tr>
</table>
</body></html>
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非常抱歉,看错题目了.
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<script language="JavaScript">
<!--
function addSrcToDestList() {
destList = window.document.forms[0].destList;
srcList = window.document.forms[0].srcList;
var len = destList.length;
for(var i = 0; i < srcList.length; i++) {
if ((srcList.options[i] != null) && (srcList.options[i].selected)) {
var found = false;
for(var count = 0; count < len; count++) {
if (destList.options[count] != null) {
if (srcList.options[i].text == destList.options[count].text) {
found = true;
break;
}
}
}
if (found != true) {
destList.options[len] = new Option(srcList.options[i].text);
len++;
}
}
}
}
function deleteFromDestList() {
var destList = window.document.forms[0].destList;
var len = destList.options.length;
for(var i = (len-1); i >= 0; i--) {
if ((destList.options[i] != null) && (destList.options[i].selected == true)) {
destList.options[i] = null;
}
}
}
// -->
</SCRIPT>
</head>
<body>
<center>
<form method="POST">
<table bgcolor="#FFFFCC">
<tr>
<td bgcolor="#FFFFCC" width="85">
<select size="6" name="srcList" multiple>
<option value="1">Item 1
<option value="2">Item 2
<option value="3">Item 3
<option value="4">Item 4
<option value="5">Item 5
<option value="6">Item 6
</select>
</td>
<td bgcolor="#FFFFCC" width="74" align="center">
<input type="button" value=" 增加到右边 " onClick="javascript:addSrcToDestList()">
<br><br>
<input type="button" value=" 从右边删除 " onclick="javascript:deleteFromDestList();">
</td>
<td bgcolor="#FFFFCC" width="69">
<select size="6" name="destList" multiple>
</select>
</td>
</tr>
</table>
</form>
</body>
</html>
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<script language="JavaScript">
function copyToList(from,to) //from表示:包含可选择项目的select对象名字 to表示:列出可选择项目的select对象名字 //你可以根据你的具体情况修改
{
fromList = eval('document.forms[0].' + from);
toList = eval('document.forms[0].' + to);
if (toList.options.length > 0 && toList.options[0].value == 'temp')
{
toList.options.length = 0;
}
var sel = false;
for (i=0;i<fromList.options.length;i++)
{
var current = fromList.options[i];
if (current.selected)
{
sel = true;
if (current.value == 'temp')
{
alert ('你不能选择这个项目!');
return;
}
txt = current.text;
val = current.value;
toList.options[toList.length] = new Option(txt,val);
fromList.options[i] = null;
i--;
}
}
if (!sel) alert ('你还没有选择任何项目');
}
function allSelect() //这是当用户按下提交按钮时，对列出选择的select对象执行全选工作，让递交至的后台程序能取得相关数据
{
List = document.forms[0].chosen;
if (List.length && List.options[0].value == 'temp') return;
for (i=0;i<List.length;i++)
{
List.options[i].selected = true;
}
}
</script>
<table border="0"> <form onSubmit="allSelect()">
<tr>
<td>
<select name="possible" size="4"
MULTIPLE width=200 style="width: 200px">
<option value="1">中国广州
<option value="2">中国上海
<option value="3">中国北京
<option value="4">中国武汉
</select>
</td>
<td><a href="javascript:copyToList('possible','chosen')">添加至右方--><br>
<br>
</a><a href="javascript:copyToList('chosen','possible')"><--添加至左方</a></td>
<td>
<select name="chosen" size="4"
MULTIPLE width=200 style="width: 200px;">
<option value="temp">从左边选择你的地区
</select>
</td>
</tr> </form>
</table>