Folks, I am new to Arduino. Need help to automate water tank (water quantity)

Hello... Need some help Getting error message when verifying the code.
Error message attached as attachment.

/*-----( Setup function )-----*/
void setup() {
  Serial.begin(9600);
  pinMode(8, INPUT_PULLUP);
}

/*-----( Loop function )-----*/
void loop() {
  boolean run_cycle = true;
  const int lowerSersor = digitalRead(8); // lower float sensor on digital pin 8

  if (lowerSersor == LOW) { // float sensor has dropped down - tank empty
    // Toggle on
    if (run_cycle) {
      sendSMS();
      run_cycle = false;
    }
  }
  if (lowerSensor == HIGH) { // tank now full
    // Toggle off
    if (run_cycle == false) {
      run_cycle = true;
    }
  }
}


//ERFINDER CODE
#include <SoftwareSerial.h>

SoftwareSerial mySerial(9, 10);

void setup()
{
  mySerial.begin(9600);   // Setting the baud rate of GSM Module  
  Serial.begin(9600);    // Setting the baud rate of Serial Monitor (Arduino)
  delay(100);
}


void loop()
{
  if (Serial.available()>0)
   switch(Serial.read())
  {
    case 's':
      SendMessage();
      break;
    case 'r':
      RecieveMessage();
      break;
  }

 if (mySerial.available()>0)
   Serial.write(mySerial.read());
}


 void SendMessage()
{
  mySerial.println("AT+CMGF=1");    //Sets the GSM Module in Text Mode
  delay(1000);  // Delay of 1000 milli seconds or 1 second
  mySerial.println("AT+CMGS=\"+923400008550\"\r"); // Replace x with mobile number
  delay(1000);
  mySerial.println("I am SMS from GSM Module");// The SMS text you want to send
  delay(100);
   mySerial.println((char)26);// ASCII code of CTRL+Z
  delay(1000);
}


 void RecieveMessage()
{
  mySerial.println("AT+CNMI=2,2,0,0,0"); // AT Command to recieve a live SMS
  delay(1000);
 }