Edit.jsp取值问题，onchange问题，求大神指导

我在edit.jsp为客户设计随写随算的功能，代扣卸费=代扣卸费单价*实际重量。利用onchange 在实际重量数据改变时，代扣卸费自动算出来
但是我的代扣卸费单价 是字典表里的数值，我在这个页面怎么用它呢，求大神指导

 function setdaiKouXieFei(){
    var daikouxiefei=  document.getElementById("ruKu.shiJiZongLiang").value* document.getElementById("dkxf").value
    document.getElementById("ruKu.daiKouXieFei").value=daikouxiefei;
}

 <TR>
        <TH align="right" width='20%'> 实际重量:</TH>
   <TD align="left" class="tdStyle" >
<s:if test="ruKu.id>0">
       <s:textfield name="ruKu.shiJiZongLiang" onchange="setdaiKouXieFei()" readonly="true" size="30"/>&nbsp;
       </s:if>
       <s:else>
           <s:textfield name="ruKu.shiJiZongLiang" onchange="setdaiKouXieFei()" readonly="true" size="30"/>&nbsp;
       </s:else>
   </TD>

//代扣卸费
    private ArrayList<Dictionary> dicDkxfdjList;
    private double dkxf;

         public ArrayList<Dictionary> getDicDkxfdjList() {
        return dicDkxfdjList;
    }
    public void setDicDkxfdjList() throws Exception{
        dicDkxfdjList = coreService.getDictionaryList("dkxf");
    }

    public double getDkxf() {
        return dkxf;
    }

    public void setDkxf() throws Exception{
        dkxf = TypeChange.stringToDouble(dicDkxfdjList.get(0).getValue());

先获取这个字典的值，放到页面中，随用随取