Accessing parent properties / casting

programming flash
1

Hi

I have a problem with accessing the properties of a parent movieclip in AS3

I have 2 movieclips on my scene: clip1 and clip2

I have some actionscript inside clip2 that I would like to use to access some properties of clip1

So I tried this code:

trace((this.parent.parent as MovieClip).clip1.y);

but I get the following error:
Access of possibly undefined property some through a reference with static type flash.display:DisplayObjectContainer.

It seems to me the path I use to get the properties of clip1 is correct, isn’t it?

Thanks in advance for your help