Question using zmodem to transfer file between two computers

HI,

Hi, I am using the Greenleaf CommX to transfer file between two computer through a modem. When I use the Greenleaf port to tranfer string, it works fine. However, when I use the Zmodem to transfer file, it doesn't work. I am using Visual Basic 6 to do the coding. Can anyone tell me an example code that can help me out? or, tell me how to do the transfer file using Zmodem. Below is the code that I wrote for my program to transfer file.

FileXferCtl1.SendFileNames = Filename
FileXferCtl1.SendFiles

Your help is really appreciated.

Thanks