I was using Jquery Numeric plugin but I found that is not working on FireFox 3.6 on Osx (does not allow pasting).
I\'m searching a Jquery plugin or Javascript snippet
Thanks to dev-null-dweller i have resolved with this script:
jQuery('#input').bind('keyup blur',function(){ jQuery(this).val( jQuery(this).val().replace(/[^0-9]/g,'') ); } );