Truyền dữ liệu giữa 2 form trong VB.Net

'hàm dùng để thực thi câu lệnh Insert    - sẽ được gọi khi nhấn nút lưu
Public Sub _Update(ByVal strLenh As String)
        open_connect()
        Dim d As String = "set dateformat dmy"
        Dim cmd1 As New SqlCommand(d, strconnect)
        cmd1.ExecuteNonQuery()

        Dim cmd As New SqlCommand(strLenh, strconnect)
        cmd.ExecuteNonQuery()
        close_connect()
    End Sub

'Hàm dùng để chạy biến ngầm khi lưu thành công
#Region "XuLy"
    Public Delegate Sub GoiDuLieuXuLy()
    Dim th_GoiDuLieu As Thread

    Public Sub start_thearing()
        th_GoiDuLieu = New Thread(AddressOf XuLyGoiDuLieu)
        th_GoiDuLieu.IsBackground = True
        th_GoiDuLieu.Start()
    End Sub

    Dim f As Boolean
    Public Sub XuLyGoiDuLieu()
        While True
            If f = True Then
                Me.BeginInvoke(New GoiDuLieuXuLy(AddressOf GoiDuLieu))
            End If
            Thread.Sleep(300)
            Exit Sub
        End While
    End Sub

    Public Sub GoiDuLieu()
        start = True
    End Sub
#End Region

 _Update("insert into tblnhanvien(manv,hoten,ngaysinh,chucvu,gioitinh,quequan,ngayvaolam) values('" & txtMaNV.Text & "',N'" & txtHoten.Text & "','" & txtNgaysinh.Text & "', N'" & cboNhanvien.Text & "','" & chkGT & "',N'" & txtQuequan.Text & "','" & txtNgayvaolam.Text & "')")
                f = True
                start_thearing()

#Region "XuLy nhận lệnh"
        Public Delegate Sub process_data()
        Dim th_NhanDuLieu As Thread
        Public Sub XuLy()
            Try
                While True
                    If start = True Then
                        Me.BeginInvoke(New process_data(AddressOf load_grid))
                    End If
                    start = False
                    Thread.Sleep(300)
                End While
            Catch ex As Exception

            End Try

        End Sub

        Public Sub start_thearing()
            th_NhanDuLieu = New Thread(AddressOf XuLy)
            th_NhanDuLieu.IsBackground = True
            th_NhanDuLieu.Start()
        End Sub
#End Region

'Hàm này dùng để load data cho grid
 Public Sub load_grid()
            Dim ds As New DataSet
            ds = _load_data("select manv,hoten,ngaysinh,chucvu, case gioitinh when 1 then 'Nam' else N'Nữ' end as gioitinh,quequan,ngayvaolam from tblNhanVien")
            'đưa source vao grid
            GridControl1.DataSource = ds.Tables(0)
        End Sub