01.
<script language=
"javascript"
>
02.
function
IsNumeric(sText,obj)
03.
{
04.
var
ValidChars =
"0123456789."
;
05.
var
IsNumber=
true
;
06.
var
Char;
07.
for
(i = 0; i < sText.length && IsNumber ==
true
; i++) {
08.
Char = sText.charAt(i);
09.
if
(ValidChars.indexOf(Char) == -1) {
10.
IsNumber =
false
;
11.
}
12.
}
13.
if
(IsNumber==
false
){
14.
alert(
"พิมพ์ได้เฉพาะตัวเลขเท่านั้น"
);
15.
obj.value=sText.substr(0,sText.length-1);
16.
}
17.
}
18.
</script>
19.
20.
21.
<input type=
"text"
name=
"number"
onKeyUp=
"IsNumeric(this.value,this)"
>