Ultrasonic sensor with LED, how can I do this?

The code works really great, but how can I improve it with this?:

When I press a button, next time the door is open (distance <10 ) a buzzer should beep. But only next time, after pressing the button.

This way you can be announced by the buzer when the door is open and the person is leaving.

I was thinking something like:

bool PressedToEnter = false;

I was thinking:

If digitalread button HIGH {

PressedToEnter == true

}

else {

PressedToEnter == false

}

If PressedToEnter == true && distance < 10 {

Buzzer

Delay

Buzzer

Delay

Buzzer

PressedToEnter == false
}

Will it work? Or there is a better way to do it.