jQuery KeyLimit Plugin for limiting key input on text forms. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. USAGE: Add 'klimit-*' to class attribute of input[type='text'] element which you want to limit key input. Just like this: <input type='text' name='number' class='klimit-digit' /> Pre-defined 'klimit-*' classes are: - klimit-digit - klimit-hex - klimit-lower - klimit-upper - klimit-alpha - klimit-alnum - klimit-graph - klimit-mail You can also make your custom rule. For instance, if you want allow user to input only alphabets, numbers, dot(.) and underscore(_) as username, this will be done with: HTML <input type='type' name='username' id='username' /> jQuery $('input#username').klimit([$.KLIMIT.ALNUM, '._']); NOTE: The key code map to convert a character into key code (event.keyCode) is based on 101 US keyboard layout by default. If you want to alter some of key codes, assign key code map to jQuery.KLIMIT.KEY_CODE_MAP prior to jquery.klimit.js is loaded. This plugin also provides 'jquery.klimit.kb109.js' which defines key codes for 106/109 Japanese keyboard as an example. So if you work with 106/109 Japanese keyboard, you should implement your HTML as below: <script src='jquery.js'></script> <script src='jquery.klimit.kb109.js'></script> <script src='jquery.klimit.js'></script>