var InputLinker = Class.create();

InputLinker.prototype = {
   initialize: function() {
      var args = $A(arguments);
      var propagate = this.propagate;
      args.each(function(item){
         var el = $(item);
         el.linkedInputs = args;
         Event.observe(item, 'click', propagate);
         Event.observe(item, 'keydown', propagate);
         Event.observe(item, 'keyup', propagate);
         Event.observe(item, 'change', propagate);
      });
      this.args = args;
   },
   
   propagate: function(event) {
      el = Event.element(event);
      el.linkedInputs.each(function(item){
         $(item).value = el.value;
      });
   }
};