Question

I am using logoff button as click then mdi form need to close and then login page should appear

Answer 1

In mobileMDI add this code:

Public Class modileMDI

    Private Sub btnLogoff_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLogoff.Click
        Login.Show()
        Me.Hide()
    End Sub
End Class

I assume the logoff button is named btnLogoff.