handle x and y of canvas code example
Example: javascript onclick select coordinates
var x;
var y;
if (e.pageX || e.pageY) {
x = e.pageX;
y = e.pageY;
}
else {
x = e.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;
y = e.clientY + document.body.scrollTop + document.documentElement.scrollTop;
}
x -= gCanvasElement.offsetLeft;
y -= gCanvasElement.offsetTop;