set a global variable called treeAnimation = 0
set a global variable called treeIsPlaying = 0
now set up a condition for each animation TreeA
ad the global variable treeAnimation = 1 to that animation condition
ad the global variable treeIsPlaying = 1 to that animation condition
(Action) set treeIsPlaying = 0 after animation
now set up a condition for each animation TreeB
ad the global variable treeAnimation = 1 to that animation condition
ad the global variable treeIsPlaying = 1 to that animation condition
(Action) set treeIsPlaying = 0 after animation
Now you can every tic set variable = int(random(1,2))
ad the global variable treeIsPlaying = 0 to that animation condition