Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        Dim regRoot As Microsoft.Win32.RegistryKey = _
        Microsoft.Win32.Registry.ClassesRoot
        Dim regSubKey As Microsoft.Win32.RegistryKey = regRoot.CreateSubKey( _
        "call")
        regSubKey.SetValue("call1", "URL:call Protocol1")
        regSubKey.SetValue("call2", "URL:call Protocol2")
        regRoot.Close()
        regSubKey.Close()
    End Sub