does it work?

static/homepage.js

@@ -270,6 +270,14 @@ function draw(){
 draw();
 window.addEventListener('scroll', draw);
 
+var current_line = 300; 
+var lines = [300, 180, 1040, 180, 1120, 480, 700, 180, 600, 180, 210, 180, 630, 1120, 260, 180];
+var r = 30; 
+var start_height = 300; 
+var speed = 10;
+var top_screen;
+var bottom_screen;
+
 function verticalLine_timeline(x, y1, y2, ctx, canvas_h) {
     if (current_line >= y1 && canvas_h >= start_height) {
         if (canDraw(y1, y2)) ctx.moveTo(x, y1);