I have got same problem, I guess it has something to do with serial
I dont know how to extract data from serial and use it in your variables.
You have to monitor the state and then get somehow the state value to your variable
Monitoring the state
#include <SoftwareSerial.h>
SoftwareSerial mySerial(7, 8);
void setup()
{
mySerial.begin(19200); // the GPRS baud rate
Serial.begin(19200); // the GPRS baud rate
delay(2000);
}
void loop() {
mySerial.println("ATV0");
delay(100);
ShowSerialData();
}
void ShowSerialData()
{
while(mySerial.available()!=0)
Serial.write(mySerial.read());
}