Object reference not set to an instance of an object. !!!

[JustRun]

Hi all,
I have a method that returns a sting array,

        public string[] GetUserRoles(Guid _userId)
        {
            arr = new string[200];
            userId = _userId;
            int i = 0;

            try
            {
                dbModule.InitConnection();
                dbModule.cmd = new SqlCommand("SELECT RoleName FROM RolesTable WHERE (UserId = @UserID)", dbModule.con);

                dbModule.cmd.Parameters.AddWithValue("UserID", userId);

                dbModule.rdr = dbModule.cmd.ExecuteReader();

                while (dbModule.rdr.Read())
                {
                    roleName = dbModule.rdr["RoleName"].ToString();
                    if (dbModule.rdr.HasRows)
                    {
                        arr[i] = roleName;
                        i++;
                    }
                    else
                    {
                        i--;
                        break;
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }

            finally
            {
                dbModule.DestroyConnection();
            }
            return arr;
        }

use this method here:

                        for (int i = 0; i < arr.Length; i++)
                        {
                            user.roleName = arr[i];
                                if (user.roleName.Equals("frmSecDailyEvents"))
                                    objFrmMain.navPaNew.Visible = true;
                                if (user.roleName.Equals("frmPermanencyReg"))
                                    objFrmMain.navPerm.Visible = true;
                                if (user.roleName.Equals("frmPatManage"))
                                    objFrmMain.navPatManage.Visible = true;
                                if (user.roleName.Equals("frmExpenses"))
                                    objFrmMain.navExpens.Visible = true;
                            }
                        }

it works fine till I get all values then I got an error at: user.roleName
Object reference not set to an instance of an object.

[JustRun]

Well, Thanks, I solved the problem.
it was the array length !! so embarrassing error :(