ผมเคยเอาโค๊ดนี้มาประยุกต์ ใช้นะครับ ก็ work ดี ลองเอาไปดูนะครับเผื่อช่วยได้
<!-- TWO STEPS TO INSTALL AUTO-SUM FORM BOXES:
1. Copy the coding into the HEAD of your HTML document
2. Add the last code into the BODY of your HTML document -->
<!-- STEP ONE: Paste this code into the HEAD of your HTML document -->
<HEAD>
<script type="text/javascript">
<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->
<!-- Created by: www.jdstiles.com -->
<!-- Begin
function startCalc(){
interval = setInterval("calc()",1);
}
function calc(){
one = document.autoSumForm.firstBox.value;
two = document.autoSumForm.secondBox.value;
document.autoSumForm.thirdBox.value = (one * 1) + (two * 1);
}
function stopCalc(){
clearInterval(interval);
}
// End -->
</script>
</HEAD>
<!-- STEP TWO: Copy this code into the BODY of your HTML document -->
Load balance : Server 04
