I found a C # source code that sends SMS with oxygen control with Oxygen control, try to debug it, and find it is really good, it is easy to use. However, it is not enough in the United States that will automatically add control company information in the sending SMS, and will cancel this information after registration, but registration requires a small fee. I downloaded the free PC Connectivity SDK3.0 directly on the Nokia website. After debugging, the same function can be achieved. The following procedure sends SMS successfully under the NOKIA8310 to connect to the computer under infrared. After installing SDK3.0, add the COM component Nokia Setting Adapter for PC Suite 3.7 and Nokiacl Messaging in the reference.