btnCalc.onRelease = function(){
//calculate angle and length from dx and dy
//use atan to get angle, pythagoras to get length
radians = Math.atan(dy/dx);
//convert to degrees
degrees = radians * 180 / Math.PI;
//offset the angle
degrees += 90;
//handle negative dx angles
if (dx <0) {
degrees -=180;
} // end if
angle = degrees;
//use pythagorean theorom to calculate length
length = Math.sqrt(dx*dx + dy*dy);
} // end btnCalc