In Adobe Animate for an HTML5/JavaScript movie, how should I change the following for rotating the graphic symbol 'VerticalRail' clock-wise by 1 degree?

At the moment it looks like it's rotating 1 degree CW, but only once. It needs to rotate constantly while button pressed.

//Right Frame Rotate CW Buttons
this.ButtonRotateCWRightFrame.addEventListener("mousedown", RF_RotateCW_Down.bind(this));

this.ButtonRotateCWRightFrame.addEventListener("pressup", RF_RotateCW_Up.bind(this));

this.ButtonRotateCCWRightFrame.addEventListener("mousedown", RF_RotateCCW_Down.bind(this));

this.ButtonRotateCCWRightFrame.addEventListener("pressup", RF_RotateCCW_Up.bind(this));


//Right Frame Rotate CW Buttons functions to move Rotate Frame CW
function RF_RotateCW_Down() {
createjs.Ticker.addEventListener("tick",updateRF_RotateCW);
}

function RF_RotateCW_Up() {
createjs.Ticker.removeEventListener("tick",updateRF_RotateCW);
}

function updateRF_RotateCW(){

 var angle = 1/Math.PI;
  root.VerticalRail.rotation = angle;
}

UPDATE

I got it working by adding a + before the = to increment the values of the rotation angle. So:

function updateRF_RotateCW(){
 var angle = 1/Math.PI;
  root.RFLensHolder.rotation += angle;
}

However, I'm wondering if this is the correct way of doing that code. Any pointers?