help with A6 gsm module + LM35

Hi everyone.I have some problem using a6 module.its working fine in case of sending sms but my problem is sending in my project.the point:i wanna make a basic temperature alarm.it will use lm35 for sensing temp and a6 module to bring it to phone.when use simple sketch of a6,it work great and it send a test message to my phone.but when i embed it in my codes,it wont.can anybody give a hand?
Here is my code:

char phone_no[]="1111111111";

int val;
int tempPin = 1;
int oldtemp;
float mv;
float cel;
void setup() {
Serial.begin(9600);




}

void loop()
{
  val = analogRead(tempPin);
mv = ( val/1024.0)*5000; 
cel = mv/10;
Serial.print(cel);
Serial.println();
 if (cel>25) {
  delay(5000);
  val=analogRead(tempPin);
  mv=(val/1024.0)*5000;
  oldtemp=mv/10;
  Serial.print(oldtemp);
  if (oldtemp>25) {
  delay(300);
 


Serial.println("AT+CMGF=1");    
delay(2000);
Serial.print("AT+CMGS=\"");
Serial.print(phone_no); 
Serial.write(0x22);
Serial.write(0x0D);  // hex equivalent of Carraige return    
Serial.write(0x0A);  // hex equivalent of newline
delay(2000);
Serial.print("Warning!cooling malfunction");
delay(500);
Serial.println (char(26));//the ASCII code of the ctrl+z is 26
  
  }
 }
 delay(1000);
}
Serial.print(cel);
Serial.println();

You must not print debugging stuff to the serial interface as you seem to have attached the A6 there. So remove all prints to the serial interface except the ones you need to send the SMS.