Why is my movie clip instance null?

I have 2 movie clips in my scene, one is charlie brown running and another is lucy lifting a football.

The movie clip instances are aptly named: lucyLi开发者_运维技巧fting and charlieRunning.

When I get to frame 75, I run the following code:

stop();
   trace(lucyLifting);
   trace(charlieRunning);

   lucyLifing.stop();
   charlieRunning.stop();

and I get the following output:

[object MovieClip]
null

Why isn't it recognizing my second movie clip instance? This is very frustrating....

Thank you in advance.

Both of your movieclips should span the entire timeline. Do they? Do you have multiple keyframes in charlieRunning? Make sure that it has an instance name at each keyframe. Otherwise, you'll need to post your FLA so we can help you.