A8C - Once key field auto-filler

oncefiller.user.js

// ==UserScript==
// @name         A8C - Once key field auto-filler
// @namespace    http://automattic.com/
// @version      0.1
// @description  Pre-fill Once fields
// @author       Remi Corson
// @match        https://<place_mc_url_here>/once/*
// @require http://code.jquery.com/jquery-latest.js
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    var getUrlParameter = function getUrlParameter(sParam) {
        var sPageURL = decodeURIComponent(window.location.search.substring(1)),
            sURLVariables = sPageURL.split('&'),
            sParameterName,
            i;

        for (i = 0; i < sURLVariables.length; i++) {
            sParameterName = sURLVariables[i].split('=');

            if (sParameterName[0] === sParam) {
                return sParameterName[1] === undefined ? true : sParameterName[1];
            }
        }
    };

    var key = getUrlParameter('key');
    $("input[name='key']").val(key);

})();

@corsonr I'd like to propose small addition. If we pop this on line 32, this can be a mouseless operation

$( 'input[type="submit"]' ).focus();

The Show Message button gets focus and you can just hit Enter on the keyboard.

I tried to go one step further and .click(); the button but that was causing all sorts of weirdness so I left it off.