Communicate between cell phone and MC ??

[felix0323]

I was using pic18f4550 and try to communicate with my cell phone(nokia 3220). I used a pl2303hx (usb to serial bridge controller) to communicate between the pinout of my cell phone and pin 23,24 (D+,D-) of the MC. But I get no response when I send AT command to the cell phone. I have used an LCD to show the feedback from the cell phone, but no response also.

So my questions are:
1. Do I need to set the baud rate or any setting for Rs232 in the MC ?
2. How can I show the feedback from the cell phone.
3. Any suggestion so that I can communicate the MC and cell phone ?

thx for all ur reply and sorry for bad language skill ....