Partial Classes: (the following 2 classes become one upon compilation even if they are defined in different files) Partial Public Class client Public Name As String = "Terry" End Class Partial Public Class client Public City As String = "Spokane" End Class (this allows the following ASP.NET page_load event to work) Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load   Dim client As New client   lblError.Text = client.Name   lblError.Text &= " of " & client.City End Sub