[MX 2004] Get Number of Frames in Movie Clip

Is it in any way possible to create a variable that represents the number of frames in a movie clip? I thought maybe something like var = getProperty(my_mc, frames); might work, but it doesn’t. I’m trying to make a “last” button for a template that goes to the last frame in a movie clip, and as we’ll be updating and changing the number of frames in the movie clip quite often, I’d rather just have it find the last frame rather than have to update the actionscript every time.

Thanks. Any help would be appreciated.