# Error why?

**URL:** <https://forum.kirupa.com/t/error-why/331927>\
**Category:** Uncategorized\
**Created:** [November 28, 2013, 1:26pm UTC](https://forum.kirupa.com/t/error-why/331927 "2013-11-28T13:26:23Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![scottiescotsman](https://avatars.discourse-cdn.com/v4/letter/s/ac91a4/32.png) [@scottiescotsman](https://forum.kirupa.com/u/scottiescotsman)\
**Post date:** [November 28, 2013, 1:26pm UTC](https://forum.kirupa.com/t/error-why/331927/1 "2013-11-28T13:26:23Z")

</div>

[AS]  
import flash.display.MovieClip;  
import com.greensock.\*;  
var array:Array = [{btn:\_about\_btn, page:\_about},  
{btn:\_services\_btn, page:\_services},  
{btn:\_portfolio\_btn, page:\_portfolio},  
{btn:\_blog\_btn, page:\_blog},  
{btn:\_contact\_btn, page:\_contact}];  
for each (var obj in array)  
{  
var b:MovieClip = obj.btn as MovieClip;  
b.buttonMode = true;  
b.mouseChildren = false;  
b.page = obj.page;  
b.addEventListener(MouseEvent.CLICK, onClick);  
}  
var curr:MovieClip;  
var prev:MovieClip = new array[0].page() as MovieClip;  
addChild(prev);  
TweenMax.from(prev, 1, {alpha:0});  
function onClick(e:MouseEvent):void  
{  
curr = new e.target.page() as MovieClip;  
TweenMax.fromTo(curr, 1, {alpha:0}, {onStart:addChild, onStartParams:[curr], alpha:1});

```
if (prev)
{
    TweenMax.to(prev, 1, {alpha:0, onComplete:removeChild, onCompleteParams:[prev]});
}

prev = curr;

```

}  
[/AS]

TypeError: Error #1009: Cannot access a property or method of a null object reference.  
at mcBlue\_fla::MainTimeline/frame21()

why am I getting this error as I am only trying to fade from one movieclip to the other

please help :huh: