Untitled

Public Class Form1

    Private Sub Form1_Resize(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Resize
        Dim myControl As Control
        myControl = sender

        ' Ensure the Form remains square (Height = Width).
        If myControl.Size.Height <> myControl.Size.Width Then
            myControl.Size = New Size(myControl.Size.Width, myControl.Size.Width)
        End If
        If myControl.Size.Height < 320 Then
            myControl.Size = New Size(319, 319)
        End If
        If myControl.Size.Width < 320 Then
            myControl.Size = New Size(319, 319)
        End If
    End Sub

End Class