javascript里如何获取GridView里某一行某一列的值和TextBox的值比较

   function CheckPayMoney(o)
   {
//       debugger;
        var obj=event.srcElement;
               
        while(obj.tagName!="TR")
        {
            obj =obj.parentElement;
        }
        var BGMoney=obj.children[4].innerText;
       
        if(parseFloat(o.value)>parseFloat(BGMoney))
        {
             alert("金额不能大于报关金额!");
             return false;
        }
       
        return true;

   
   }