How do you use Loading a Random background on the website

I found the loading random background tutorial
http://www.kirupa.com/developer/mx/loadingrandombackground.htm,
so i follow through the tutorial to make my .swf file work as every time i open the .swf file, it gives me different background. However, when i insert its in my webpage, it gives me no response. It won’t even load or do anything else at all, so is there anything i need to do or any specific code that i need to include when i insert it to my webpage so it’ll load the new background everytime that i refresh the page?

By the way, the tutorial’s really helpful, thank you!