Update draw_image.html

Add (event) in two places, at line 210, 211. Because in some browsers there is a throw exception, in console.log().

pages/draw_image.html

@@ -207,8 +207,8 @@ <h3>Extra</h3>
 
 		// DRAWING EVENT HANDLERS
 
-		canvas.addEventListener('mousedown', function() {mousedown(canvas, event);});
-		canvas.addEventListener('mousemove',function() {mousemove(canvas, event);});
+		canvas.addEventListener('mousedown', function(event) {mousedown(canvas, event);});
+		canvas.addEventListener('mousemove',function(event) {mousemove(canvas, event);});
 		canvas.addEventListener('mouseup',mouseup);
 
 		// CREATE CANVAS
@@ -339,4 +339,4 @@ <h3>Extra</h3>
 			isMouseDown=false
 			store()
 		}
-</script>
+</script>