float sinVal;
int toneVal;
boolean stateAlarm;

void setup(){
pinMode(2,INPUT_PULLUP);
pinMode(7,OUTPUT);
}

void loop(){
if(digitalRead(2)==LOW){
stateAlarm=!stateAlarm;
delay(300);
}

if(stateAlarm==1){
for(int x=0;x<180;x++){

// convert degrees to radians then obtain sin value
sinVal = (sin(x*(3.1412/180)));

// generate a frequency from the sin value
toneVal = 2000+(int(sinVal*1000));

tone(7, toneVal);

delay(2);
if(digitalRead(2)==LOW){
stateAlarm=!stateAlarm;
delay(300);
}
}
}
else{
noTone(7);
}

}