unable to call hub method

Question

i have below code /function ,it gives error ,

 

if i check same issue in chrome it says

 

Uncaught TypeError: Cannot read property 'sendPrivateMessage' of undefined

at HTMLInputElement.<anonymous> (LetsChat:180)

at HTMLInputElement.dispatch (jquery-1.10.2.min.js:22)

at HTMLInputElement.v.handle (jquery-1.10.2.min.js:22)

 

in forefox it says below (same issue)

 

TypeError: chat.server is undefinedLetsChat:180:21

function createPrivateChatWindow(userId, ctrId, userName,chat) {
      alert("createPrivateChatWindow method")

      var div = '<div id="' + ctrId + '" class="ui-widget-content draggable" rel="0">' +
                  '<div class="header">' +
                      '<div  style="float:right;">' +
                          '<img id="imgDelete"  style="cursor:pointer;" src="/Images/delete.png"/>' +
                      '</div>' +

                      '<span class="selText" rel="0">' + userName + '</span>' +
                      '<span class="selText" id="msgTypeingName" rel="0"></span>' +
                  '</div>' +
                  '<div id="divMessage" class="messageArea">' +

                  '</div>' +
                  '<div class="buttonBar">' +
                      '<input id="txtPrivateMessage" class="msgText" type="text"   />' +
                      '<input id="btnSendMessage" class="submitButton button" type="button" value="Send"   />' +
                  '</div>' +
                  '<div id="scrollLength"></div>' +
              '</div>';

      var $div = $(div);

      // Send Button event
      $div.find("#btnSendMessage").click(function () {
          alert(chat)
       //   console.log(chat.connectionid)
          alert("send click")

          $textBox = $div.find("#txtPrivateMessage");
          var msg = $textBox.val();
          alert("msg is  " + msg)
          if (msg.length > 0) {
              chat.server.sendPrivateMessage(userId, $("#connlbl").text(), msg, 'Click');
              $textBox.val('');
          }
      });

      // Text Box event
      $div.find("#txtPrivateMessage").keyup(function (e) {
          if (e.which == 13) {
              $div.find("#btnSendMessage").click();
          }

          // Typing
          $textBox = $div.find("#txtPrivateMessage");
          var msg = $textBox.val();
          if (msg.length > 0) {
            //  chat.server.sendPrivateMessage(userId, msg, 'Type');
          }
          else {
             // chat.server.sendPrivateMessage(userId, msg, 'Empty');
          }

       //   clearInterval(refreshId);
       //   checkTyping(chat, userId, msg, $div, 5000);
      });

      AddDivToContainer($div);
  }

here is hub method function

public void SendPrivateMessage(string toUserId,string fromuserid ,string message, string status)
{
}