# 1120 Undefined Property Event

**URL:** <https://forum.kirupa.com/t/1120-undefined-property-event/321469>\
**Category:** flash\
**Created:** [April 20, 2011, 5:36pm UTC](https://forum.kirupa.com/t/1120-undefined-property-event/321469 "2011-04-20T17:36:34Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![zz\_](https://avatars.discourse-cdn.com/v4/letter/z/e56c9b/32.png) [@zz\_](https://forum.kirupa.com/u/zz_)\
**Post date:** [April 20, 2011, 5:36pm UTC](https://forum.kirupa.com/t/1120-undefined-property-event/321469/1 "2011-04-20T17:36:34Z")

</div>

First off, I’d like to say that yes, I read the sticky, and yes, I’ve searched for solutions. The problem is, however, that I’m a super-noob when it comes to flash (done it for a total of a day now) and I simply do not understand the solutions that are given, and the ones that I do understand don’t solve the issue.

Alright:

I’m trying to make an object (more specifically a circle) move upon command, yet I keep running into this error: “ **1120: Access of undefined property event.** ” As I’ve understood it this error has something to do with the object being a null value, but I don’t understand how to fix this.

```auto

circle_mc.addEventListener(event.ENTER_FRAME, moveCircle);

function moveCircle(event:Event):void
{
    if(rightKeyIsDown)
    {
        circle_mc.x+=15
    }
    if(leftKeyIsDown)
    {
        circle_mc.x-=15
    }
}

```

If someone could help me out here I’d be greatly appreciative.