This script allow only numeric values in the text fields

onlynumeric.js

$('body').on('keydown', 'input[name=random]', function(e) {
        return ((e.keyCode >= 48 && e.keyCode <= 57) || (e.keyCode >= 96 && e.keyCode <= 105) || e.keyCode == 173 || e.keyCode == 8 || e.keyCode == 9) ? true : false;
});