var canvas = document.getElementById('c1');
var ctx = canvas.getContext('2d');
canvas.onmousemove = function(event){
canvas.onmousedown = function(event){
var x = event.offsetX;
var y = event.offsetY;
console.log(x);
console.log(y);
ctx.flllRect(x-5,y-5,5,5);
}
}