jquery 操作listbox 左右相互选择

实现左右两个listbox的相互选择功能

代码如下:

         function ListBox_Move(listfrom, listto) {
             var size = $j("#" + listfrom + " option").size();
             var selsize = $j("#" + listfrom + " option:selected").size();
             var strvalue = "";
             if (size > 0 && selsize > 0) {
                 $j.each($j("#" + listfrom + " option:selected"), function(i, own) {
                     var sText = $j(own).text();
                     var sValue = $j(own).val();
                     var flag = true;
                     $j.each($j("#" + listto + " option"), function(id, ownto) {
                         if ($j(ownto).val() == sValue) {
                             flag = false;
                         }
                     });
                     if (flag) {
                         $j("#" + listto).append("<option value=\"" + sValue + "\">" + sText + "</option>");
                         strvalue += $j(own).text() + ":" + $j(own).val();
                         strvalue += ",";
                     }
                     $j(own).remove();
                     $j("#" + listfrom + "").children("option:first").attr("selected", true);
                 });
             } else {
                 if (listfrom=='listbCos') {
                     alert('请先选择要导入的信息！');
                 } else {
                     alert('请先选择要删除的信息！');
                 }
             }
         }

界面元素：

 　　　　　<td width="28%">
            <input id="txtCos" type="text"  width="100%" />
            <select  id="listbCos"  multiple="Multiple" style="width: 200px; height: 130px;"></select>
          </td>
          <td align="center " width="12%"><br/> <br/> <br/>
             <input type="button" id="btnImport" value="    导入>>    " style="cursor :pointer"  onclick="ListBox_Move('listbCos','listbContent')"/><br/><br/>
             <input type="button" id="btnDel" value="    <<删除    "   style="cursor :pointer" onclick="ListBox_Move('listbContent','listbCos')"/><br/> <br/><br/>
          </td>
          <td width="28%">
              <select  id="listbContent"  multiple="Multiple" style="width: 200px; height: 150px;"></select>
          </td>