function selected(thiz) {  var name = thiz.name;  if(name=="right")   $("select[name='left']").val("");  else   $("select[name='right']").val(""); } function Shift(thiz) {  var right = $("select[name='right']");  var left = $("select[name='left']");  if(thiz=="left" && right.val() != ""){   lrShift(right,left);  }else if(thiz=="right" && left.val() != ""){   lrShift(left,right);  }   //獲取選中的值 } //從dest移動到target function lrShift(dest,target) {  var childrens = dest.children();  var args = "";  //alert(dest.val());  var dests = dest.val()  for(var x = 0; x < dests.length; x++)  {   var vaTemp = dests[x];   target.append("<option value='"+vaTemp+"'>"+vaTemp+"</option>");//追加   target.find("option[value='"+vaTemp+"']").attr("selected",true);//給追加獲取焦點   for(var y = 0; y <childrens.length;y++ )//刪除選中的元素   {    if(childrens.get(y).value==vaTemp)     $(childrens.get(y)).remove();   }  }  dest.val(""); } function ShiftValue(address) {  var right = $("select[name='right']");  var left = $("select[name='left']");  if(right.val()!=null)   shift(right,address);  else if(left.val()!=null)   shift(left,address); } function shift(obj,address){   //獲取選中的值   var objData = obj.val();   var childrens = obj.children();   var strs = "";   for(var x = 0; x < objData.length; x++)   {    strs+="@"+objData[x];   }    //獲取要添加位置對象   var temp = null;   if(address=="top"){    var number = findSelect(childrens,objData[0]);    if((--number) < 0)     return;    temp = childrens.get(number);   }   else{    var number = findSelect(childrens,objData[objData.length-1]);    if((++number) > childrens.length-1)     return;    temp = childrens.get(number);   }    //刪除選中的值   var n = 0;   var buffer = new Array(childrens.length-objData.length);   for(var x = 0; x < childrens.length;x++)   {    var value = childrens.get(x).value;    if(strs.indexOf(value)==-1)     buffer[n++] = value;   }    //添加新排序的值   obj.empty();   if(address=="top")   {    for(var y = 0; y < buffer.length;y++)    {     if(buffer[y]==temp.value)     {      for(var x = 0; x < objData.length ; x++)      {       obj.append("<option>"+objData[x]+"</option>");      }     }     obj.append("<option>"+buffer[y]+"</option>");    }   }else{    for(var y = 0; y < buffer.length;y++)    {     obj.append("<option>"+buffer[y]+"</option>");     if(buffer[y]==temp.value)     {      for(var x = 0; x < objData.length; x++)      {       obj.append("<option>"+objData[x]+"</option>");      }     }    }   }   //選中值   obj.val(objData); } function findSelect(selects,objValue) {  var number = -1;  for(var x = 0; x < selects.length; x++)  {   if(objValue==selects.get(x).value)    number = x;  }  return number; } 

<div>   <div>    <b>未導出字段</b>   </div>   <div style="float:left;">    <select name="left" multiple="multiple" onchange="selected(this)" style="height:350px;width:200px;">     <option value="姓名">姓名</option>     <option value="快件號">快件號</option>     <option value="快遞公司">快遞公司</option>     <option value="首重">首重</option>     <option value="續重">續重</option>    </select>   </div>  </div>  <div style="float:left;">   <div style="margin:30px;margin-top:110px;">   <input type="button" value="<<" onclick="Shift('left')"/>  </div>   <div style="margin:30px;margin-top:30px;">   <input type="button" value=">>" onclick="Shift('right')"/>  </div>  </div>  <div style="margin-top:-20px;">   <div style="margin-left:22%;">    <b>需導出字段</b>   </div>   <div style="float:left;">    <select name="right" multiple="multiple" onchange="selected(this)" style="height:350px;width:200px;">     <option value="首價">首價</option>     <option value="續價">續價</option>     <option value="大大">大大</option>     <option value="小小">小小</option>    </select>   </div>  </div>  <div style="float:left;">   <div style="margin:30px;margin-top:110px;">   <input type="button" value="向上" onclick="ShiftValue('top')" />   </div>   <div style="margin:30px;margin-top:30px;">   <input type="button" value="向下" onclick="ShiftValue('bottom')" />  </div>  </div>