Control of Main Movie from Symbol Movies

To help keep things organized, I built movie clip symbols to keep my main movie timeline clean, and placed the symbols inside of the main movie. I would like to do something like this:

if (movie symbol is finished playing)
{
gotoandplay(3) --- movie clip finished, move to the next one
} else {
gotoandplay(1) --- movie clip not finished, keep looping
}

Any ideas on how to get the main timeline to continue from a movie symbol?

Thank you,

~ Nick