Userscripts.org

// ==UserScript==
// @name           Userscripts.org "Add Script" Number Only Input
// @namespace      http://userscripts.org/users/23652
// @description    Paste a script link into the "Add Script" field, and it will get turned into that script's ID
// @include        http://userscripts.org/groups/*/scripts
// @copyright      JoeSimmons
// @version        1.0.0
// @license        Creative Commons Attribution-Noncommercial 3.0 United States License
// ==/UserScript==

function filter(e) {
if(e.value!='') e.value = e.value.replace(/[^\d]*/g, '');
}

var add = document.evaluate("//input[@type='text' and @name='script_id']",document,null,9,null).singleNodeValue;
if(add) {
add.addEventListener('change', function(e){filter(e.currentTarget);}, false);
add.addEventListener('blur', function(e){filter(e.currentTarget);}, false);
add.addEventListener('focus', function(e){filter(e.currentTarget);}, false);
}