Com-port => you need the serial communication library. There's plenty of free c++ serial communication libraries, try google. For detailed info about AT commands see documentation for partial type of your mobile phone. For example, look at scmxx library for communicating with Siemens mobiles. You can read many useful commands from the scmxx source code :). Good luck! Robert-Antonio "A piece of paper is an ink-lined plane. An inclined plane is slope up. A slow pup is a lazy dog. Q.E.D.: A piece of paper is a lazy dog."