绑定与取消绑定…该功能完成后如何再次绑定？

var foo =  $(\"div\").bind(\"click\", function() {
    $(\"div\").animate({\"height\" : \"500px\"}, 2000);
    $(\"div\").animate({\"height\" : \"50px\"}, 2000);
    $(\"div\").unbind();
    });

function handler() {
    $(this)
     .unbind()
     .animate({\"height\" : \"500px\"}, 2000);
     .animate({\"height\" : \"50px\"}, 2000, function(){
         $(this).click(handler); // <- gets called once the animation finishes
     });
}

$(\'div\').click(handler);