How to change the code to work automatically instead of using Play button?

programming flash
1

Hi,

The following code draws a square on using Play Button. But I want it to be started drawing automatically without using the Play Button. I got the example code from searching the google.

import com.greensock.*;
import flash.events.MouseEvent;

//create line
var line:Shape = new Shape();
addChild(line);

//position mc at first point
mc.x = p1.x;
mc.y = p1.y;

var tl:TimelineMax = new TimelineMax({paused:true,onUpdate:drawLine});

tl.appendMultiple([
  TweenLite.to(mc, 1, {x:p2.x, y:p2.y}),
  TweenLite.to(mc, 1, {x:p3.x, y:p3.y}),
  TweenLite.to(mc, 1, {x:p4.x, y:p4.y}),
  TweenLite.to(mc, 1, {x:p1.x, y:p1.y})
  ], 0, TweenAlign.SEQUENCE);


function drawLine():void
{
    line.graphics.lineTo(mc.x, mc.y);
}

play_btn.addEventListener(MouseEvent.CLICK, playTl);

function playTl(e:MouseEvent):void
{
    //kill existing line
    line.graphics.clear();
    
    //start new line at first point
    line.graphics.lineStyle(2, 0xFFFF00, .5);
    line.graphics.moveTo(p1.x, p1.y);
    
    tl.restart();
}

Please do help.