http://keith-wood.name/keypad.html
Keypad field entry extension for jQuery v1.2.1.
Written by Keith Wood (kbwood{at}iinet.com.au) August 2008.
Dual licensed under the GPL (http://dev.jquery.com/browser/trunk/jquery/GPL-LICENSE.txt) and 
MIT (http://dev.jquery.com/browser/trunk/jquery/MIT-LICENSE.txt) licenses. 
Please attribute the author if you use it.