programa_3

<canvas width="600" height="400"> </canvas>

<script>


var pantalla=document.querySelector("canvas");

var pincel=pantalla.getContext("2d");

pincel.fillStyle="grey";

pincel.fillRect(0,0,600,400);

  function exhibirAlerta(evento){

    var x= evento.pageX - pantalla.offsetLeft;
    var y= evento.pageY - pantalla.offsetTop;


   console.log(x + "," + y);


  }


   function dibujarCirculo(evento){

    var x= evento.pageX - pantalla.offsetLeft;
    var y= evento.pageY - pantalla.offsetTop;

    pincel.fillStyle="blue";
    pincel.beginPath();
    pincel.arc(x,y,10,0,2*3.14);
    pincel.fill();



   console.log(evento);

   alert(x + "," + y);

  }

 //pantalla.onclick=exhibirAlerta;

  pantalla.onclick=dibujarCirculo;

</script>