JavaScript Validation for Integer

<script language="javascript" type="text/javascript">

        function numeralsOnly(e) {
            var keycode;

            if (window.event) {
                keycode = window.event.keyCode; //alert('IE');
            }
            else if (e) {
                keycode = e.which; //alert('FF');
            }

            var k = parseInt(keycode);
            if (k > 47 && k < 58 || k == 13) {
                e.returnValue = true;
                return true;
            }
            e.returnValue = false;
            return false;
        }       
    </script>
onkeypress="return numeralsOnly(event)"
[10:47:25 AM] Vivek Sahu: onkeypress="return numeralsOnly(event)"