[JS] Phone number validation

 function phoneNumberValidationByID(phoneNumber) {
    var $phoneNumber = $("#" + phone-number);

    // Set max number length
    $phoneNumber.attr('maxlength','9');

    // Allowed keys
    $phoneNumber.keydown(function (e) {
      if ($.inArray(e.keyCode, [46, 8, 9, 27, 13, 110, 190]) !== -1 || // Allow: backspace, delete, tab, escape, enter and .
        (e.keyCode == 65 && (e.ctrlKey === true || e.metaKey === true)) || // Allow: Ctrl/cmd+A
        (e.keyCode == 67 && (e.ctrlKey === true || e.metaKey === true)) || // Allow: Ctrl/cmd+C
        (e.keyCode == 88 && (e.ctrlKey === true || e.metaKey === true)) || // Allow: Ctrl/cmd+X
        (e.keyCode >= 35 && e.keyCode <= 39)) { // Allow: home, end, left, right
        return; // let it happen, don't do anything
      }

      // Ensure that it is a number and stop the keypress
      if ((e.shiftKey || (e.keyCode < 48 || e.keyCode > 57)) && (e.keyCode < 96 || e.keyCode > 105)) {
        e.preventDefault();
      }
    });

    // check if length = 9
    $phoneNumber.on('keyup', function () {
      $phoneNumber.val().length == 9 ? $phoneNumber.addClass('correct') : $phoneNumber.removeClass('correct');
      if ($phoneNumber.val().length == 9) {
        $phoneNumber.addClass('correct');
        $phoneNumber.removeClass('invalid');
      } else {
        $phoneNumber.addClass('invalid');
        $phoneNumber.removeClass('correct');
      }

    });
  }