มีปัญหาการส่งข้อมูลจาก User Control ไป windows form //Object reference not set to an instance of an object.

Public Class member
    Dim invoice As invoice 'invoice คือ usercontrol
    Private Sub gridviewshow_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles gridviewshow.KeyDown
        If e.KeyCode = Keys.Enter Then
            invoice.txtMem.Text = (gridviewshow.CurrentRow.Cells("mem_id").Value)
            invoice.txtMemName.Text = (gridviewshow.CurrentRow.Cells("mem_name").Value)
            invoice.txtMemSername.Text = (gridviewshow.CurrentRow.Cells("mem_sername").Value)
            invoice.txtHMem.Text = (gridviewshow.CurrentRow.Cells("mem_Hid").Value)
            invoice.txtHMemName.Text = (gridviewshow.CurrentRow.Cells("mem_Hname").Value)
            invoice.txtHMemSername.Text = (gridviewshow.CurrentRow.Cells("mem_Hsername").Value)
            invoice.txtAddress.Text = (gridviewshow.CurrentRow.Cells("mem_address").Value)
            Me.Close()
            invoice.txtProID.Focus()
        End If

    End Sub
End Class