外部评级系统的问题，TypeError：$（...）。live不是一个函数

Question

我对JS非常苛刻，我正在尝试实施这个评级系统，http://www.technabled.com/2011/02/pulse-lite-reddit-ajax-up-down-voting.html

但是当我用firebug检查它时，我得到了这个错误，任何可能出错的线索？

TypeError：$（...）。live不是函数

$("input.pulse_vote_button").live('click', function(){

这就是JS：

$(function(){
var u = "/post/Pulse"; // NO trailing slash; Same as PULSE_DIR in pulse.config.php
$("input.pulse_vote_button").live('click', function(){
    var item_id = $(this).attr("data-itemId"); // id of the item to vote
    var format = $(this).attr("data-format"); // result format
    var dir = $(this).attr("data-dir"); // voting direction; up or down
    el = $(this);
    result = el.parent().next(".pulse_result_format").text();
    el.parent().next(".pulse_result_format").html(" <img class='busy' src='"+u+"/assets/images/ajaxloader.gif'/> "); // show loading animation
    el.parent().children(".pulse_vote_button").each(function(){
        $(this).attr("disabled","disabled"); // disable buttons
        $(this).addClass('disabled');
    });
    $.ajax({
        type: "POST",
        data: "action="+dir+"&item_id="+item_id+"&format="+format,
        url: u+"/votes.php",
        dataType: 'json',
        error: function(a,b){
            alert("Cannot connect to database. Please try again.");
            el.parent().children(".pulse_vote_button").each(function(){
                $(this).removeAttr("disabled"); // disable buttons
                $(this).removeClass('disabled');
            });             
            el.parent().next(".pulse_result_format").text(result);
        },
        success: function(obj)
        {
            if('error' in obj){
                switch(obj.error){
                    case "already_voted":
                        alert("You have already voted");
                        el.parent().next(".pulse_result_format").text(result); // clear the loader and replace with result
                        break;
                    case "database_error":
                        alert("Cannot connect to database. Please try again.");
                        el.parent().children(".pulse_vote_button").each(function(){
                            $(this).removeAttr("disabled"); // disable buttons
                            $(this).removeClass('disabled');
                        }); 
                        el.parent().next(".pulse_result_format").text(result); // clear the loader and replace with result
                        break;
                }
                return false;
            } if('msg' in obj) {
                var re = /\\/g; 
                obj.msg = obj.msg.replace(re, "");
                el.siblings(".busy").remove(); // remove loader
                el.parent().next(".pulse_result_format").text(obj.msg); // insert the formatted result
                el.parent().next(".pulse_result_format").show();
            }
        }
    });
 });
});