I am using following code to send massage using arduino uno & GSM800 module. But I need to send same massage on multiple numbers then what changes should i make in my code..Please help..??

const int buttonPin = 8;   // Main gate sensor 1
const int buttonPin1 = 7;  // Main gate sensor 2
const int buttonPin2 = 9;  // Store room sensor 1
const int buttonPin3 = 10; // Store room sensor 2

bool i = false;
bool j = false;
bool k = false;
bool l = false;

void setup()
{
  Serial.begin(9600);
  
  pinMode(buttonPin, INPUT);
  pinMode(buttonPin1, INPUT);
  pinMode(buttonPin2, INPUT);
  pinMode(buttonPin3, INPUT);

  digitalWrite(buttonPin, LOW);
  digitalWrite(buttonPin1, LOW);
  digitalWrite(buttonPin2, LOW);
  digitalWrite(buttonPin3, LOW);

  delay(1000);
}
void loop()

{
  sensor1();
  sensor2();
}
  void sensor1()
  {
  if (digitalRead(buttonPin1)== LOW && digitalRead(buttonPin) == HIGH  && i == false)

  {
    Serial.println("OK");
    delay(1000);
    Serial.print("AT+CMGF=1\r\n");
    delay(500);
    Serial.print("AT+CMGS=\"");
    Serial.print("+91...................");
    Serial.print("\"\r\n");
    delay(2000);
    Serial.print("Main Gate is Closed");
    Serial.write(0x1A);
    delay(1000);
    i = true;
    j = false;
   
  }
  
  if (digitalRead(buttonPin)== LOW && digitalRead(buttonPin1) == HIGH &&  j == false)
  {
    Serial.println("OK");
    delay(1000);
    Serial.print("AT+CMGF=1\r\n");
    delay(500);
    Serial.print("AT+CMGS=\"");
    Serial.print("+91........................");
    Serial.print("\"\r\n");
    delay(2000);
    Serial.print("Main Gate is open");
    Serial.write(0x1A);
    delay(1000);
    j = true;
    i = false;
  }
  }
  void sensor2()
  {
  if (digitalRead(buttonPin2) == HIGH && digitalRead(buttonPin3)==LOW && k == false)
  {
    Serial.println("OK");
    delay(1000);
    Serial.print("AT+CMGF=1\r\n");
    delay(500);
    Serial.print("AT+CMGS=\"");
    Serial.print("+91....................");
    Serial.print("\"\r\n");
    delay(2000);
    Serial.print("Store room is Closed");
    Serial.write(0x1A);
    delay(1000);
    k = true;
    l = false;
  }
  if (digitalRead(buttonPin3) == HIGH &&digitalRead(buttonPin2)== LOW && l == false)
  {
    Serial.println("OK");
    delay(1000);
    Serial.print("AT+CMGF=1\r\n");
    delay(500);
    Serial.print("AT+CMGS=\"");
    Serial.print("+91....................");
    Serial.print("\"\r\n");
    delay(2000);
    Serial.print("Store room is Open");
    Serial.write(0x1A);
    delay(1000);
    l = true;
    k = false;
  }
}

Advance Thanks Nilesh Surwade