[Moo] Trouble getting removeEvent to work

[Ryan Florence]

Here's a small class, my detach method doesn't work.  I haven't done  
much with removeEvent, not sure what the problem is here.  When I call  
detach on the object, it doesn't detach the submit handler.

Request.JSON.Form = new Class({
        
        Extends: Request.JSON,
                
        initialize: function(form,options){
                this.parent(options);
                this.form = $(form);
                this.options.url = this.form.get('action');
                this.attach();
        },
        
        attach: function(){
                this.form.addEvent('submit',this.submit_handler.bind(this));
                return this;
        },
        
        detach: function(){
                this.form.removeEvent(this.submit_handler);
                return this;
        },
        
        submit_handler: function(event){
          event.stop();
          this.post(this.form);
        }
        
});