Hi Imam if you are facing a problem like me and don't know how to go about programming the ISR for serial interrupt go through this thread
http://www.8052.com/forum/rea...&top=66485

remember serial comm ISR transmission is like a domino effect..http://www.cogsci.princeton.edu/cgi-bin/w...ino+effect

you transmit once then get into isr then in the isr you pick the next charachter to transmit and again TI is set due to this transmission ...you clear the ti and gain transmit the next char... the cycle continue

You will require a circular buffer I remeber Hans telling me to search for this key word.

If this doesn't solve your problem .. we are here.

Deepak