Functions question in Animate Canvas

I’m a little confused regarding communication between functions as the code below throws an undefined error.

What I’m trying to accomplish, is a simple way that I can turn a group of EventListeners on and off. - Peter

function startListen() {

  var binderbp1 = bp1_click.bind(this);

  this.bp1.addEventListener(“click", binderbp1);

  var binderbp2 = bp1_click.bind(this);

  this.bp1.addEventListener(“click", binderbp2);

  var binderbp3 = bp1_click.bind(this);

  this.bp1.addEventListener(“click", binderbp3);

}

function endListen() {

  this.bp1.removeEventListener("click", binderbp1);

  this.bp2.removeEventListener("click", binderbp2);

  this.bp3.removeEventListener("click", binderbp3);

}

startListen();

endListen();