function distance(x1,y1,x2,y2) {
    //find horizontal distance (x)
    var x = x2 - x1;
    //find vertical distance (y)
    var y = y2 - y1;
    //do calculation
    var hyp = Math.sqrt(x*x + y*y);
    return hyp;
  }

  function map(fractional, min, max){
    return Math.abs(fractional) * (max - min) + min;
  }