Sending files !!!

Hallo Guys

I am very new in VB but I make my first project
it is a winsock program acting as a client and server
(chat program)
i tried it many times on the net and it works so nice
but now i want to add sending file as a new thing in it but i didn't know how to do it
i try to learn
* internet tranfer protocol (HTTP,FTP) but fail to use it to send and recived
* internet comm but failed too

i am dreamd about ake it
browse ==> select file ==> OK ==> the program send a signal to the anthor one ==> the other tell the user there is file coming where he want to save it ==> the other user browse and select new name ==> save ==> the transfere begin and can continue chating during the sending procces

i know i will use commen dialog to open and save but how that all mechanisms work

help guys


!! SORRY FOR MY ENGLISH I HOPE I MAKE IT CLEAR ENOUGH !!