01.<input name="id_card_txt" type="text" id="id_card_txt" onKeyPress="if (event.keyCode < 48 || event.keyCode > 57 ){event.returnValue = false;}" maxlength="13">
02.<input type="submit" name="Submit" value="Check id card" onClick="id_card(document.getElementById('id_card_txt'))">
03.
04.<script>
05.function check_idcard(idcard){
06. if(idcard.value == ""){ return false;}
07. if(idcard.length < 13){ return false;}
08.
09.var num = str_split(idcard);
10.var sum = 0;
11.var total = 0;
12.var digi = 13;
13.
14. for(i=0;i<12;i++){
15. sum = sum + (num[i] * digi);
16. digi--;
17. }
18. total = ((11 - (sum % 11)) % 10);
19.
20. if(total == num[12]){
21. return true;
22. }else{
23. return false;
24. }
25.}
26.
27.
28.function str_split ( f_string, f_split_length){
29. f_string += '';
30. if (f_split_length == undefined) {
31. f_split_length = 1;
32. }
33. if(f_split_length > 0){
34. var result = [];
35. while(f_string.length > f_split_length) {
36. result[result.length] = f_string.substring(0, f_split_length);
37. f_string = f_string.substring(f_split_length);
38. }
39. result[result.length] = f_string;
40. return result;
41. }
42. return false;
43.}
44.
45.function id_card(id){
46. if(check_idcard(id.value)){
47. alert("ID Card Completed.");
48. }else{
49. alert("ID Card Error ?\nPlease Tye Again");
50. id.value = "";
51. id.focus();
52. }
53.}
54.</script>
