01.<!DOCTYPE html>
02.<html>
03.<body>
04.
05.<script type="text/javascript">
06.var r = 0;
07.var oV;
08.function check_total(val, idx){
09. var tal = document.getElementsByName("radim[" + idx + "]");
10. var point = parseInt(val);
11. var hP = 1000;
12.
13. var sum = parseInt(document.getElementById("txt1").value);
14. if (r === 0) {
15. sum += point;
16. oV = parseInt(document.getElementById("txt1").value);
17. } else {
18. sum = oV + point;
19. }
20.
21. if(sum > hP){
22. alert("แต้มไม่พอ");
23. return false;
24. }
25. document.getElementById("txt1").value = sum;
26. r++;
27.}
28.</script>
29.
30.<input type="text" name="txt1" id="txt1" value="500" readonly><br>
31.
32.<?php
33.$num = array(200,100,300);
34.$no=1;
35.for($i=0;$i<3;$i++){
36. echo $no.".1 <input type='radio' name='radim[".$i."]' value='".$num[$i]."' onchange='check_total(this.value,$i);'>";
37. echo $no.".2 <input type='radio' name='radim[".$i."]' value='".($num[$i]*2)."' onchange='check_total(this.value,$i);'><br>";
38. $no++;
39.}
40.?>
41.
42.
43.</body>
44.</html>
