Making A Messenger Client?

i am trying to make a messenger client which will work like alerter or similar, so far i have decided to to make two applications,

1) which will send messenger,(sender)

2) which will accept msg and display a alert to user using msgbox.(receiver)

i have started coding receiver, i am using port 6000 to listen to messenger.so far i have made code to listen to port(open/bind/listen)but now i am not able to figure out how to display messages to user received on that port.

Dim RecieveSocket As Socket
Dim PortListen As Int16 = 6000
Dim address As IPAddress = IPAddress.Parse("0.0.0.0")
Dim endpoint As New IPEndPoint(address, PortListen)

[code]....