int BUTTON1 = 7;
int BUTTON2 = 6;
int RED     = 3;
int Buzzer  = 9;
int button1;
byte button2;
int ledRed;

void setup ()
{
    Serial.begin (9600);     // initializing serial communication.
    Serial.println ("Waiting for User Input");

    pinMode (RED, OUTPUT);   // Defining LED pin as output.

    pinMode (BUTTON1, INPUT_PULLUP); // Defining Button pin as INPUT_PULLUP.
    pinMode (BUTTON2, INPUT_PULLUP); // Defining Button pin as INPUT_PULLUP.
    pinMode (Buzzer, INPUT);         // Defining Buzzer pin as INPUT

    button1 = digitalRead (BUTTON1); // Reading BUTTON1 and putting the output as a var named button1
    button2 = digitalRead (BUTTON2); // Reading BUTTON2 and putting the output as a var named button2
    
}

void loop ()
{
    byte but = digitalRead (BUTTON1);    // up
    if (button1 != but)  {
        button1 = but;
        delay (20);         // debounce

        if (LOW == but)  {
            ledRed += 10;       //increase LED brightness by 10
            if (255 < ledRed)   //check if the LED bightness is below 255
            ledRed = 255;
            Serial.println (ledRed);
            analogWrite (RED, ledRed);
        } if (ledRed == 255) {
            digitalWrite(Buzzer, HIGH);
            delay(500);
            digitalWrite(Buzzer, LOW);
            delay(500);     
        }
    }

    but = digitalRead (BUTTON2);    // down
    if (button2 != but)  {        //checking if button2 is not equal to the but var (Button Down)
        button2 = but;            //set button2 var to but var
            delay (20);         // debounce

        if (LOW == but)  {
            ledRed -= 10;
            if (0 > ledRed)
                ledRed = 0;
                Serial.println (ledRed);
                analogWrite (RED, ledRed);
        } if (ledRed == 0) {
            digitalWrite(Buzzer, HIGH);
            delay(500);
            digitalWrite(Buzzer, LOW);
            delay(500);     
        }
    }
}