actionscript math ramndom?

Sorry but last time forgot 2 put points for my dear helping Expert!
Here is the question and my code.
The question is that Im tryng to build an educational quiz with a set amount of questions to be outputted! How do I make sure that the same question is not repeated and that once il questions are put forward the program exits?
Here is my initial code. Hope u can help me would be very educational 4 me
Many thanks! (hope I havent been mean with the points! I think it may be easy 4 an expert!)


words=["Which is the capitol of Italy?","Which is the capitol of Spain?","Which is the capitol of France?","Which is the capitol of Holland?"];
randvalue=Math.round(Math.random()*4);
word=words[randvalue];
trace(word);