Transistions to each 5 seconds?How

I already have certainty that he gives to make random, I looked for in the search of the forum, what I found, I was half lost, example, I have 4 mcs of transistions, that go to be random, alone that almost mine mcs of the transistions is all inside of the flash, as I make each one to appear to each 5 seconds?
as I make they to be random?

sorry about my English.