Error while trying to retrieve attributes of a lookup record.

Hello. I am trying to retrieve a lookup record attributes. Here is my part of code in which i am getting an error:

function RetrieveAccountReqCallBack(RetrieveAccountReq) {
    debugger;
    var retr = RetrieveAccountReq.readyState;
    if (RetrieveAccountReq.readyState ==1 /* complete */) {
           var RetrievedAccount = this.parent.JSON.parse(RetrieveAccountReq.responseText).d;
            if(RetrievedAccount.new_level!=null)
                Xrm.Page.getAttribute("new_level").setVisible(false);
            if(RetrievedAccount.new_count!=null)
                Xrm.Page.getAttribute("new_count").setVisible(false);
                      }
        else {
            errorHandler(RetrievedAccount);
            alert("Error in Fetch Account data");
        }    }

I am getting an error on this line : this.parent.JSON.parse(RetrieveAccountReq.responseText).d;

and the error i am getting is : The data necessary to complete this operation is not yet available

Please help!