ctx.strokeStyle = "rgba(200,0,0,0.6)";
    ctx.lineWidth = 4.0;
    //ctx.lineJoin = "round";
    ctx.beginPath();
    ctx.moveTo(lastpos.x, lastpos.y);
    ctx.lineTo(pos.x, pos.y);
    ctx.closePath();
    ctx.stroke();
      
    lastpos = pos;
  }