# Null object reference

**URL:** <https://forum.kirupa.com/t/null-object-reference/316342>\
**Category:** Uncategorized\
**Created:** [November 18, 2010, 9:16pm UTC](https://forum.kirupa.com/t/null-object-reference/316342 "2010-11-18T21:16:06Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![bonassus](https://avatars.discourse-cdn.com/v4/letter/b/ea5d25/32.png) [@bonassus](https://forum.kirupa.com/u/bonassus)\
**Post date:** [November 18, 2010, 9:16pm UTC](https://forum.kirupa.com/t/null-object-reference/316342/1 "2010-11-18T21:16:06Z")

</div>

this code is working:

```auto
for(i = 0; i < 8; i++){
 graphicDesignArray*.addEventListener(MouseEvent.ROLL_OVER,buildOverGDThumb(i));
            }

    function buildOverGDThumb(number:Number): Function {
        var thisVar: Object = this;
        var over: Function = function(event:MouseEvent){
        var target = event.target;
        thisVar.setChildIndex(target,thisVar.numChildren - 1);
        TweenMax.to(graphicDesignArray[number],.5,{scale:thumbScaleOver,x:thumbPosXArray[number],y:thumbPosYArray[number],ease:Back.easeOut});
            
        }
        return over;
    }

```

I’m getting the error:Cannot access a property or method of a null object reference with this:

```auto
for(var i = 0; i < 8; i++){ graphicDesignArray*.addEventListener(MouseEvent.CLICK,buildOnGDThumb(i));
            }

function buildOnGDThumb(number:Number): Function {
    
        var onFunction: Function = function(event:MouseEvent){
                if(imageState == "off"){
               
            thumbTimelineArray[number] = new TimelineLite();
            thumbTimelineArray[number].insertMultiple([
            TweenMax.to(graphicDesignArray[number],.5,{scale:1,x:450,y:350,ease:Back.easeOut}),
            TweenMax.to(whiteBg,.5,{scale:1,x:0,y:0,ease:Back.easeOut}),
            ], 0, TweenAlign.START, 0.3);
                imageState = "on"
                }else{
            TweenMax.to(graphicDesignArray[number],.5,{scale:thumbScaleOver,x:thumbPosXArray[number],y:thumbPosYArray[number],ease:Back.easeOut});
                
                imageState = "off"
                }
        }
        return onFunction;
    }

```

I don’t know why.