gridview not displaying in webpage

 i have to display grid view for the logged in user say for my manager i have written the stored procedure and back end code for it everything looks fine but grid view is not gettin populated please help me

back end code of grid view

public DataSet GetManager(MTMSDTO M)
                  {
                   DBAccess db = new DBAccess();
                   SqlParameter objParam = new SqlParameter("@EmpName", M.EmpName);
                   objParam.Direction = ParameterDirection.Input;
                   objParam.Size = 50;

                   db.Parameters.Add(objParam);
                   return db.ExecuteDataSet("GetManager");
                  }

                public DataSet GetManager(MTMSDTO M)
                { 
                  MTMSAccess obj = new MTMSAccess();
                  return obj.GetManager(M);
                }


                 protected void Page_Load(object sender, EventArgs e)
                {
                 MTMSDTO objc = new MTMSDTO();

                  if (!IsPostBack)
                  {
                    GrdManager();
                  }
                }

                   protected void GrdManager()
                    {
                      MTMSDTO objc = new MTMSDTO();
                       {
                        objc.EmpName = Convert.ToString(Session["EmpName"]);
                        DataSet GrdMA = obj.GetManager(objc);
                        DataView GrdMan = new DataView();
                        GrdMan.Table = GrdMA.Tables[0];
                        GridViewTTlist.DataSource = GrdMan;
                        GridViewTTlist.DataBind();
                       }
                     }

my stored procedure
ALTER PROCEDURE [dbo].[GetManager]

               @EmpName nvarchar(50)

               AS

               Select TaskName, DueDate, Description, AssignBy, AssignTo, Status,  PercentageComplete

               From  dbo.Task, dbo.EmployeeData

               Where AssignTo in (Select EmpName From EmployeeData Where Manager = 'RaghavendraS') 

               And AssignBy in (Select EmpName From EmployeeData Where Manager = 'RaghavendraS')

               And EmpName = @EmpName;