สอบถามเรื่อง การใส่จำนวนแสดงผลลัพธ์ ทันที ผมได้นำ code การใส่จำนวนลงไปใน text แล้วแสดงผลลัพธ์เลย

<script type="text/javascript">
function doCalSum(Record, Qty, Price){
var Sum;
Sum = parseInt(Qty) * parseFloat(Price);
document.getElementById("hdnSum" + Record).value = Sum.toFixed(2);
document.getElementById("spnSum" + Record).innerHTML = Sum.toFixed(2);
doCalTotal();
}

function doCalTotal(){
var Record = document.getElementById("hdnCount").value;
var Total = 0;
for(i=1;i<=Record;i++){
Total += parseFloat(document.getElementById("hdnSum" + i).value);
}
document.getElementById("spnTotal").innerHTML = Total.toFixed(2);
}
function digitsOnly(obj){
var regExp = /[0-9]$/;
if(!regExp.test(obj.value)){
obj.value = obj.value.substring(0, obj.value.length -1);
return false;
}
}
</script>

 <table width="715" cellpadding="0" cellspacing="1" bordercolor="#FF9FAA">
          <tr align="center" bgcolor="#FF9FAA" class="normal_font">
            <td width="5%" height="22">ลบ</td>
            <td width="15%">รหัสสินค้า</td>
            <td width="12%">ประเภทสินค้า</td>
            <td width="23%">สินค้า</td>
            <td width="12%">จำนวน</td>
            <td width="18%">ราคา / หน่วย </td>
            <td width="15%" colspan="2">รวม            </td>
          </tr>
          <?php 
              
for($i=0;$i<count($sess_id);$i++){ 
$total_unit=$sess_num[$i]*$sess_price[$i];                                      
$total=$total+$total_unit; 
$code=sprintf("%05d",$sess_id[$i]);               
?>
          <tr align="center" bgcolor="#F3F3F3">
            <td><input name="prd_del[]" type="checkbox" id="prd_del[]" value="<?=$sess_id[$i]?>" /></td>
            <td class="style6"><input name="hdnId1" type="hidden" id="hdnId1" />
            <?=$code?></td>
            <td height="22" class="style6"><?=$sess_type[$i]?></td>
            <td class="style6"><?=$sess_name[$i]?></td>
            <td><input name="txtQty1" type="text" id="txtQty1" style="text-align:center" onkeyup="digitsOnly(this);doCalSum(1, this.value,'<?=$sess_price[$i]?>')" value="<?=$sess_num[$i]?>" size="5" /></td>
            <td class="style6"><? echo number_format($sess_price[$i],2);?></td>
            <td class="style6"><span name="spnSum1" id="spnSum1"><? echo number_format($total_unit,2);?></span>
            <input name="hdnSum1" type="hidden" id="hdnSum1" value="1" /></td>
          </tr>
          <?
            
}
        
?>
          <tr>
            <td height="22" colspan="8" align="right" class="normal_font">&nbsp;</td>
          </tr>
          <tr bgcolor="#D4DFAA">
            <td height="22" colspan="8" align="right" bgcolor="#FFFFFF" class="style8"><span class="style12">
              <input name="hdnCount" type="hidden" id="hdnCount" value="1"/>
            จำนวนราคาทั้งหมด </span> <span class="style10"><span name="spnTotal" id="spnTotal"><? echo number_format($total,2);?></span></span> <span class="style12">บาท</span></td>
          </tr>
          <tr>
            <td height="22" colspan="8" align="right">&nbsp;</td>
          </tr>
          <tr>
            <td height="22" colspan="8" align="right"><input name="button" type="button" onclick="window.location='script_logout.php' " value="ยกเลิกการสั่งซื้อ" />
            <input name="continuebuy"  type="button" id="continuebuy" onclick="window.location='productall.php' " value="กลับไปซื้อสินค้า" />
<input name="complete" type="button" id="complete" value="สั่งซื้อสินค้า" onclick="window.location='order.php' " />            </td>
          </tr>
        </table>