Class myform
        Inherits Form
 
        Public Property Value() As String
            Get
                Return Me.Text
            End Get
            Set(ByVal value As String)
                Me.Text = value
            End Set
        End Property
 
        Public Sub New(ByVal value As String)
            Me.Value = value
        End Sub
 
    End Class

        Dim fo As New myform("Hallo")
        fo.Value = "Hallo" ' optional
        fo.ShowDialog()