Randomize Banner

Here I have 11 different banners that are swf files which I wanted to call one by one, but randomly, as the user refreshs the page. (ie. everytime the user open the website he can always see a new banner on his page) Below, I have given the script and all you need to make 11 different swf files and name them like Bannner1, Banner2, etc. Below is the script:

itemtotal = 11;
fscommand("flashpath");
temptotal = itemtotal;
movieprefix = "http://www.yourpath.com/flash/bannerset/banner";
aItemTemp = new Array();
aMovie = new Array();
newvar = math.round((math.random()*9)+1);
loadMovieNum(movieprefix+(newvar)+".swf", 1);