PaulS:
It appears that you are using the Serial pins to talk to the XBee and to talk to the PC. That really isn't a good idea.
Actually, i'm trying to use serial communication to communicate with three XBees Sir. Right now I'm focusing on getting just one End device to work first before i moved on to make End device 2 work. I am able to send the value across the end device from the master. I need to get the end device to light up the LED in the Switch case statement as well to have a complete prototype ready to submit.