求助！请问怎么用arduino写gprs的程序

雪城无月

我找了一个gprs的例程，用来发信息，可是不知道为什么不行，部分代码如下，求指教：
#include <SoftwareSerial.h>
#include <String.h>

SoftwareSerial mySerial(7, 8);

void setup(){
  mySerial.begin(19200);               // the GPRS baud rate   
  Serial.begin(19200);    // the GPRS baud rate
  delay(500);
}

void loop(){
  //after start up the program, you can using terminal to connect the serial of gprs shield,
  //if you input 't' in the terminal, the program will execute SendTextMessage(), it will show how to send a sms message,
  //if input 'd' in the terminal, it will execute DialVoiceCall(), etc.

  if (Serial.available())
    switch(Serial.read()){
     case 't':
       SendTextMessage();
       break;
     case 'd':
       DialVoiceCall();
       break;
     case 'h':
       SubmitHttpRequest();
       break;
     case 's':
       Send2Pachube();
       break;
   }
  if (mySerial.available())
    Serial.write(mySerial.read());
}

///SendTextMessage()
///this function is to send a sms message
void SendTextMessage(){
  mySerial.print("AT+CMGF=1\r");    //Because we want to send the SMS in text mode
  delay(100);
  mySerial.println("AT + CMGS = \"+8615989071155\"");//send sms message, be careful need to add a country code before the cellphone number
  delay(100);
  mySerial.println("A test message!");//the content of the message
  delay(100);
  mySerial.println((char)26);//the ASCII code of the ctrl+z is 26
  delay(100);
  mySerial.println();
}

Jerry

你要用gprs上网功能发信息？
看你描述不清楚，所以特来回复一下