Help needed working with arduino - Xbee API mode

Hi all, I have been trying to get my Xbee series 2 module to work in the API mode but was unable to do so. I have the coordinator connected to the arduino and the router/end device connected to my computer. I basically want these modules to be able to send messages back and forth. It would be of great help if you can tell me which firmware to load and also the setting required for the same in Xbee series 2.

I'm amazed at the number of people that buy mesh-network modules to do point-to-point work. Why didn't you get the point-to-point versions?