Buttons and animations problem

Ok hers the problem I have four buttons set up in my very early portfolio and each button triggers a fade out animation of the boxes on the stage and then fades in the boxes that corresponds to the button pushed, the issue being that if i was to push the buttons non consecutively it plays the wrong fade out animation. How can I check to see which page the user is on so the fade out animation plays correctly?

Cheers,
Inept