Javascript：TypeError：$ .chat不是函数

Question

我有以下javascript代码段，它定义了聊天功能，它应该在Sharepoint站点中创建聊天。 但是我得到“TypeError：$ .chat不是函数”，有谁知道我怎么能解决这个问题？

编辑：当我尝试调用此函数时出现此错误：

$(document).ready(function() {
  $.chat({
    listguid: "{3A076D9D-362B-455A-8F19-831F6716B6F0}"
  });
});

(function($) {
  $.chat = function(options) {
    $.chat.settings = $.extend({
        listguid: '0',
        divid: 'jQueryChatBox',
        savecaption: 'Send',
        clearcaption: 'Clear',
        messagecolumn: 'Message'
      },
      options || {});
    ChatBox = "<input type='text'  size='50' id='" + $.chat.settings.divid + "textbox' name='" + $.chat.settings.divid + "textbox'/><br/><input type='submit' id='" + $.chat.settings.divid + "submitbutton' value='" + $.chat.settings.savecaption + "'/><input type='reset' value='" + $.chat.settings.clearcaption + "'/>";
    $('#' + $.chat.settings.divid).html(ChatBox);
    $('#' + $.chat.settings.divid + 'submitbutton').click(
      function() {
        if ($.trim($('#' + $.chat.settings.divid + 'textbox').val()) == "")
          return false;
        var soapEnv = "<?xml version=\"1.0\" encoding=\"utf-8\"?> <soap:Envelope xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\"> <soap:Body> <UpdateListItems xmlns=\"http://schemas.microsoft.com/sharepoint/soap/\"> <listName>" + $.chat.settings.listguid + "</listName> <updates> <Batch OnError=\"Continue\"> 	<Method ID=\"1\" Cmd=\"New\"> <Field Name=\"" + $.chat.settings.messagecolumn + "\">" + $('#' + $.chat.settings.divid + 'textbox').val() + "</Field> </Method> </Batch> </updates> </UpdateListItems> </soap:Body> </soap:Envelope>";
        $.ajax({
          url: L_Menu_BaseUrl + "/_vti_bin/lists.asmx",
          beforeSend: function(xhr) {
            xhr.setRequestHeader("SOAPAction", "http://schemas.microsoft.com/sharepoint/soap/UpdateListItems")
          },
          type: "POST",
          dataType: "xml",
          data: soapEnv,
          contentType: "text/xml; charset=utf-8"
        });
        $('#' + $.chat.settings.divid + 'textbox').val('');
        return false;
      })
  }
})
(jQuery);
$(document).ready(function() {
  $.livelistdata({
    prompt: false,
    interval: 100,
    opacity: '0.5'
  })
});