Ah, right, you want a set of unique numbers. Here is a tutorial for that:
Generating Random Numbers Without Duplicates
Not very elegant solution in my taste, but it should do you well. What I normally use is a Fischer-Yates shuffle method (google it), as demonstrated here:
<img src="https://dl.dropboxusercontent.com/u/629300/Images/shuffle.png" border="0">
I just iterate through the function results and draw the frames in supplied order.