Receive offline messages with Quickblox

I used the query below to retrieve previous posts.

let resPage = QBResponsePage(limit:100, skip:self.messageHandler.messageArray.count)
let parameters = ["sort_desc" : "date_sent"]
QBRequest.messagesWithDialogID(createdDialog.ID, 
                               extendedRequest: parameters, 
                               forPage: resPage, 
                               successBlock: 
                               {(response: QBResponse, messages: [QBChatMessage]?, responcePage: QBResponsePage?) in
                               /*** You will get all the previous messages ***/
                               }, 
                               errorBlock: {(response: QBResponse!) in
                               /*** Some error occured while getting messages ***/
                               })