Drag object around a circle on mouse over - Adobe Animate/Create.js/Easel.js

Question

Using Adobe Animate HTML5 Canvas which employs Create.js/Easel.js.

I have the following code which drags an object around a circle.

Works Ok, but the object should only be moveable when the cursor is over the object; object being streakRotatorKnob.

var knob_X = 454;
var knob_Y = 175;
var radius = 80;

root.streakRotatorKnob.addEventListener("pressmove",moveF.bind(this));

function moveF(e){ 
var rads = Math.atan2(stage.mouseY-knob_Y,stage.mouseX-knob_X);
e.currentTarget.x = knob_X + radius * Math.cos(rads);
e.currentTarget.y = knob_Y + radius * Math.sin(rads);
stage.update();
}

I have tried the following but it's not working at all with the if statement:

var knob_X = 454;
var knob_Y = 175;
var radius = 80;

root.streakRotatorKnob.addEventListener("pressmove",moveF.bind(this));

function moveF(e){
    if(stage.mouseY == root.streakRotatorKnob.y && stage.mouseX == root.streakRotatorKnob.x){
var rads = Math.atan2(stage.mouseY-knob_Y,stage.mouseX-knob_X);
e.currentTarget.x = knob_X + radius * Math.cos(rads);
e.currentTarget.y = knob_Y + radius * Math.sin(rads);
stage.update();
    }
}