closes #44: make x,y into local variables not global

    var rh1, con, ts;

    var lat, lon;

    x = (p.x - this.x0)/this.k0;

    y = (this.rh - (p.y - this.y0)/this.k0);

    var x = (p.x - this.x0)/this.k0;

    var y = (this.rh - (p.y - this.y0)/this.k0);

    if (this.ns > 0) {

      rh1 = Math.sqrt (x * x + y * y);

      con = 1.0;