Preloader help

hi all, im VERY new to flash. i have learnt a bit through kirupa tho :wink:
i am trying to incorporate an egg preloader so that there is a percentage below the entire egg, but that as the percentage increases, the inside, or yellow, of the egg (the yoke) fills from down to up (such as water being filled in a tank, or as a clock. i am having trouble with the code.