Need some help loading external image

Hello. First let me state that I am new to flash so excuse my ignorance.
I am doing a tutorial from the kirupa site(http://www.kirupa.com/developer/flashcs3/loading_image_as3_pg1.htm)
and I have a question.

How can I have this swf reload the image every five seconds? the file name stays the same, but the image changes every 5 seconds and I would like the swf to show the updated images.
Thanks for your help.
Cheers!

dXh