Movement on random time

Hi there,

i want to make a movement. An object has to come from behind an object and go back again. The interval between each time the object appears has to be random.
i was trting to maken something with the setTimer() function, and a random. The random gives a var. This var i would use as time for the object appears in combination with the setTimer()
Problem is that i can’t come up with a decent code that would work.

been a long time i used AS so i need somebody who can help me with this, simple, code. Where do i need to define the start vars, adn where do i define the random script.

greetz