GSM Based Door Lock

#include<SoftwareSerial.h> 
SoftwareSerial mySerial(10,11);  // (Rx,Tx  > Tx,Rx) 

char incomingByte; 
String inputString;
int IN1 = 2; // Output for Motor Driver IN1
int IN2 = 3; // Output for Motor Driver IN2

void setup() 
{
      pinMode(IN1, OUTPUT);
        pinMode(IN2, OUTPUT);
      digitalWrite(IN1, LOW); // Initial state of the LOW
       digitalWrite(IN2, LOW); // Initial state of the LOW
      Serial.begin(9600);
      mySerial.begin(9600); 

     while(!mySerial.available()){
        mySerial.println("AT");
        delay(1000); 
        Serial.println("Connecting...");
        }
      Serial.println("Connected!");  
      mySerial.println("AT+CMGF=1");  //Set SMS to Text Mode 
      delay(1000);  
      mySerial.println("AT+CNMI=1,2,0,0,0");  //Procedure to handle newly arrived messages(command name in text: new message indications to TE) 
      delay(1000);
      mySerial.println("AT+CMGL=\"REC UNREAD\""); // Read Unread Messages
     }

void loop()
{  
  if(mySerial.available()){
      delay(100);

      // Serial Buffer
      while(mySerial.available()){
        incomingByte = mySerial.read();
        inputString += incomingByte; 
        }

        delay(10);      

        Serial.println(inputString);
        inputString.toUpperCase(); // Uppercase the Received Message

        //turn RELAY ON or OFF
        if (inputString.indexOf("DOOR LOCK") > -1){      // Send sms for door lock
          digitalWrite(IN1, HIGH);
          delay(500);
          digitalWrite(IN1, LOW);
          }
            
           if (inputString.indexOf("DOOR UNLOCK") > -1){     //send sms for door unlock
          digitalWrite(IN2, HIGH);
          delay(500);
          digitalWrite(IN2, LOW);
          }
        
        delay(50);

        //Delete Messages & Save Memory
        if (inputString.indexOf("OK") == -1){
        mySerial.println("AT+CMGDA=\"DEL ALL\"");

        delay(1000);}

        inputString = "";
  }
}