Not able to talk to remote terminal

sirs,
i am using sz/rz command for calling to a remote computer for a unix based machine. When using these commands in foreground it is working fine... But when r using these commands in the background i am not able to call to the remote computer. sz/rz commands are properitory of OMAN TECHNOLOGIES
kindly help in this matter plz.......
NOTE : sz : it is used to transmit the file to the remote computer
rz : it is used to receive the file from the remote computer

                                                     - manikumar

Hi Manikumar,
can you truss the command and please send to me the output.
Moshe