​x
 
<html>
<body>
<script type="text/javascript">
function noNumbers(e)
{
var keynum
var keychar
var numcheck
​
if(window.event) // IE
    {
    keynum = e.keyCode
    }
else if(e.which) // Netscape/Firefox/Opera
    {
    keynum = e.which
    }
keychar = String.fromCharCode(keynum)
numcheck = /\d/
return !numcheck.test(keychar)
}
</script>
​
<form>
Type some text (numbers not allowed):
<input type="text" onkeypress="return noNumbers(event)" />
</form>
​
</html>
​