Arduino wait for change in value I am currently working on a project that involves steering wheels, and I would like a way for Arduino to wait for a change in value. A potentiometer is used and I would like a program to run (say, like lights blinking ) until there is a change in value of the potentiometer ( like an increase in 300). 

Thanks in advance.

EDIT
I realized that I did not give enough information about what I want, so here is the actual task I am trying to achieve :

The lights goes on when : 

Button is pressed

The lights goes off when :

The button is pressed again

or

Another button is pressed

or

Potentiometer increases or (only one of it) decreases by 300

Plus I didn't mention that the value of the potentiometer will be constantly changing so the old value for the potentiometer should be the one right after the button press. 

Soooo sorry for the inconvenience caused. ( I am really bad at programming)
int oldValue;
void setup()
{
    oldValue = analogRead(A1);
}

void loop()
{
    int value = analogRead(A1);
    while( abs(value-oldValue)&lt;300 )
        delay(1);
    oldValue = value;

    // start blinking lights here, as the value has changed by at least 300

}