FF4 adv. help!!!

In FF4 advance, I heard u could revieve your fallen comrades by going behind the crystal room in Mysidia after beating the Tower of Babel. I’m doing this, and it aint working. Is it because I now have to use that room for the people’s praying about the Lunar Whale?
WHAT DO I DO?! PLZ HELP!!!

You can’t rejoin your former comrades until after the events in the Giant of Babel. Your location is correct, though.

And how do I get to these events?

Well, that’s part of the story, and I try not to spoil that for people. How far into the game are you?

I think the FF4 shrine’s walkthrough should suffice here:

http://www.rpgclassics.com/shrines/snes/ff4ht/walk/

It doesn’t cover any of the GBA version’s additions, but it should help you get to the Giant of Babil.