gsm dfrobot send and receive sms

hi guys i want to asking how arduino to read an sms , and send sms back to cellphone. i use df robot gsm shield V3
when i send L to gsm shield, it will receive the sms and send me back to my cellphone sms DATA1=10
but when i send H, gsm shield send me sms DATA1=10, it should send me DATA2=20.

i want to ask how about the program if i use word like DATA1 and send me back DATA1=10

i want to use this gsm for temperature monnitoring with ds18b20, and i still confused how arduino read and send me SMS back.

this is my sketch

byte gsmDriverPin[3] = {
  3,4,5};//The default digital driver pins for the GSM and GPS mode
//If you want to change the digital driver pins
//or you have a conflict with D3~D5 on Arduino board,
//you can remove the J10~J12 jumpers to reconnect other driver pins for the module!
char inchar;
int dat1 = 10;
int dat2 = 20;
void setup()
{   
  //Init the driver pins for GSM function
  for(int i = 0 ; i < 3; i++){
    pinMode(gsmDriverPin[i],OUTPUT);
  }
  Serial.begin(9600);                                      //set the baud rate
  digitalWrite(5,HIGH);                                     //Output GSM Timing
  delay(1500);
  digitalWrite(5,LOW); 
  digitalWrite(3,LOW);                                      //Enable the GSM mode
  digitalWrite(4,HIGH);                                     //Disable the GPS mode
  delay(2000);
  delay(5000);                                              //call ready
  delay(5000);
  Serial.println("AT+CMGD=1,4");                           //Delete all SMS in box
}
 
void loop()
{ 
  if(Serial.available())
  {
    inchar=Serial.read();
    if(inchar=='T')
    {
      delay(10);
      inchar=Serial.read();
      if (inchar=='I')                                      //When the GSM module get the message, it will display the sign '+CMTI "SM", 1' in the serial port
      {     
        delay(10);
        Serial.println("AT+CMGR=1");                       //When Arduino read the sign, send the "read" AT command to the module
        delay(10);
      }
    }
    if (inchar=='L')
    {
      delay(10);
      inchar=Serial.read();                                     //Thw SMS("LH") was display in the Serial port, and Arduino has recognize it.
      {
        Serial.println("AT");  
  delay(2000);
  //Send message
  Serial.println("AT+CMGF=1");
  delay(1000);
  Serial.println("AT+CMGS=\"+6289682765367\"");//Change the receiver phone number
  delay(1000);
  Serial.print("DATA1= ");//the message you want to send
  delay(1000);
  Serial.print(dat1);
  delay(1000);
  Serial.write(26);
        delay(10);
                        
             
        Serial.println("AT+CMGD=1,4");                  
        delay(500);
      }}
          if (inchar=='H')
    {
      delay(10);
      inchar=Serial.read();                                     //Thw SMS("LH") was display in the Serial port, and Arduino has recognize it.
      {
        Serial.println("AT");  
  delay(2000);
  //Send message
  Serial.println("AT+CMGF=1");
  delay(1000);
  Serial.println("AT+CMGS=\"+6289682765367\"");//Change the receiver phone number
  delay(1000);
  Serial.print("DATA2= ");//the message you want to send
  delay(1000);
  Serial.print(dat2);
  delay(1000);
  Serial.write(26);
        delay(10);
                         //Turn on led
             
        Serial.println("AT+CMGD=1,4");                    //Delete all message
        delay(500);
      }}}}