sned & receive data ,ProgressBar & EOF problem

hi
I 'm writing a programm in VB with mscomm that send and receive data via modem and i want when open file in PC1 and read from file and send to another PC and write it in a file, show a progress bar and show that a file is sending from pc1 to pc2 with Progress bar.
i can  works in text mode and read binary mode from file and send file to another pc and i can another problem is that i can send text file but i can't receive another types of file(pics or exe file) .and i don't know how can in receive procedure, i can find end of file or recognize my all data of file have been received and close received file. that when pc1 send another file i can save this file too. because if i can't close old file i can't save new fie
please help me.