jquery.inputNumbersOnly.js

  $(".ui-number input").keydown(function (e) {
    if ($.inArray(e.keyCode, [46, 8, 9, 27, 13, 110, 190]) !== -1 ||
        (e.keyCode === 65 && (e.ctrlKey === true || e.metaKey === true)) ||
        (e.keyCode >= 35 && e.keyCode <= 40)) {
             return;
    }
    if ((e.shiftKey || (e.keyCode < 48 || e.keyCode > 57)) && (e.keyCode < 96 || e.keyCode > 105)) {
        e.preventDefault();
    }
    if ( $(this).val().length > 5 ){
      e.preventDefault();
    }
  });