jQuery: constrain input chars plugin

Problem:
you need to only allow the user to input certain characters into the input box, and you want a jquery plugin to do it!

Solution:

(function($){
$.fn.constrainInput = function(config){
   var settings = $.extend({
      allowedCharsRegex: ".*"
   }, config);
      var re = new RegExp(settings.allowedCharsRegex);
   $.each(this, function(){
     var input = $(this);
    
     var keypressEvent = function(e){
       e= e || window.event;
       var k = e.charCode || e.keyCode || e.which;
       if(e.ctrlKey || e.altKey || k == 8){//Ignore
         return true;
       } else if ((k >= 41 && k <= 122) ||k == 32 || k > 186){//typeable characters
         return (re.test(String.fromCharCode(k)));
       }
       return false;
     }
     input.bind("keypress",keypressEvent);
   });
   return this;
 };
})(jQuery);

//usage:

the following lets you specify which chars (regexes or'ed together) are allowed in the input.

i added a small demo for the plugin, check it out here

get the plugin here