Error Showing Forms

[MJM]

Can anyone help with this problem plz...

I'm trying to display / hide forms but I keep coming up with an error.

Here's the code:

frmMain.vb

Public Class frmMain
    Inherits System.Windows.Forms.Form
    Dim LoginForm As New frmLogin

    Private Sub btnQuit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnQuit.Click
        Me.Close()
    End Sub

    Private Sub btnLogIn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLogIn.Click
        Me.Hide()
        LoginForm.Show()
    End Sub

frmLogin.vb

Public Class frmLogin
    Inherits System.Windows.Forms.Form
    Dim MainForm As New frmMain

    Private Sub btnBack_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBack.Click
        Me.Hide()
        MainForm.Show()
    End Sub
End Class

When I try to run this code I get no compile errors, but then I get a "Just-In-Time Debugging" pop-up, with the error: "An exception 'System.StackOverflowException' has occurred".

I'm really stuck on this now so any help would be great.

TIA MJM