Stupid flash variable question

I have a question… this should be easy but I’m stuck.

This

emptymc.imageMC[x].Size

returns small

This

emptymc.imageMC[x].myArg1

(where myArg1 is small) returns undefined

I know that flash is probably looking for a variable called myArg1 inside the movie clip but it’s supposed to look for small.

Any help?