03.<head>
04.<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
05.<title>Untitled Document</title>
06.</head>
07.<body>
08.<SCRIPT Language="JavaScript">
09.
10.function startCalc(){
11.interval = setInterval("calc()",1);
12.}
13.function calc(){
14.one = document.autoSumForm.target.value;
15.
16.document.autoSumForm.gap.value = parseInt(one * 1) * parseInt(150);
17.}
18.function stopCalc(){
19.clearInterval(interval);
20.}
21.</SCRIPT>
22.
23.<form name="autoSumForm" id="">
24.จำนวนเดือน <select name="target" id="target" onFocus="startCalc();" onBlur="stopCalc();">
25. <option value="">-----กรุณาเลือกระยะเวลา-----</option>
26. <?php
27. for($i=1;$i<=24;$i++){
28. ?>
29. <option value="<?php echo $i ;?>"> <?php echo $i ;?> เดือน</option>
30. <?php } ?>
31. </select>
32.==> ผลรวม <input type="text" name="gap" id="gap" value="">
33.</form>
34.
35.</body>
36.</html>
