关键代码如下：

<tablecellpadding="0" cellspacing="0" border="0">
    <tr>
        <td style="">
            <select name="sel_place1" multiple="multiple" size="8" style="width: 100px;">
                <option>数学</option>
                <option>语文</option>
                <option>外语</option>
                <option>英语</option>
                <option>化学</option>
            </select>
        </td>
        <td style="">
            <input type="button" id="add" value=">>" onclick="allsel(document.form1.sel_place1,document.form1.sel_place2)" /><br />
            <br />
            <input type="button" id="del" value="<<" onclick="allsel(document.form1.sel_place2,document.form1.sel_place1)" />
        </td>
        <td style="height: 106px; width: 103px;">
            <select name="sel_place2" multiple="multiple" size="8" style="width: 100px;">                                      
            </select>
        </td>
    </tr>
</table>

关键的js代码：

<scriptlanguage="javascript" type="text/javascript">
            function allsel(n1,n2)  
            {
              while(n1.selectedIndex!=-1)
              {
                 var indx=n1.selectedIndex;          //获取选择的值
                 var t=n1.options[indx].text;        //显示文本
                 var v=n1.options[indx].value;       //值
                 n2.options.add(new Option(t,v));    //从左边移到右边
                 n1.remove(indx);                    //移除左边
              }
            }
                        
            
            function
            {
                var ids="";                
                var
                var
                for(var
                {
                    ids += ","+c[i].value;                                       
                }
                
                document.getElementById("subId").value = ids.substring(1);
                //alert(document.getElementById("subId").value);
            }
    </script>

 

下拉列表的相关操作_input