int buttonpin1=12;
int buttonpin2=11;
int buttonval1;
int buttonval2;
int dt=1500;
int dt2=1000;
int ledbright=0;
int ledpin=3;
int buzzpin=13;
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(buttonpin1, INPUT);
pinMode(buttonpin2, INPUT);
pinMode(ledpin, OUTPUT);
pinMode(buzzpin,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
buttonval1=digitalRead(buttonpin1);
buttonval2=digitalRead(buttonpin2);
Serial.print ("button 1 = ");
Serial.print (buttonval1 );
Serial.print(", ");
Serial.print ("button 2 = ");
Serial.println (buttonval2 );
delay(dt);

if (buttonval1==0){
ledbright=ledbright+30;
}

if (buttonval2==0){
ledbright=ledbright-30;
}

if (ledbright>255){
ledbright=255;
digitalWrite(buzzpin,HIGH);
delay(dt2);
digitalWrite(buzzpin,LOW);
Serial.println("BUZZ HIGH");
}

if (ledbright<0){
ledbright=0;
digitalWrite(buzzpin,HIGH);
delay(dt2);
digitalWrite(buzzpin,LOW);
Serial.println("BUZZ HIGH");
}

analogWrite(ledpin,ledbright);
}