[thelist] image caching

At 12:21 AM 4/6/00 -0700, you wrote:
>peter,
>
>there are several ways to do this.
>
>something else you could try is appending a random number to the end of the
>image source string.  the browser will think, because of the query string,
>that it should check for a new version.  here's an example of how i might
>handle it.

Actually, I've been waiting to write, because I've run into a bit of a 
problem with something like this. For banner ads (served with AdJuggler) 
I'm using ASP to generate the random number, since the site's on an IIS 
server. Very simple. Works like a charm--but  the Sorcerer's Apprentice 
learned the danger of charms: It works too well, in some situations:

The problem is, when I visit one of these pages with the browser I use to 
check my work, the banners are *constantly* changing while everything else 
on the page remains constant. Animated GIFs go through one cycle, 
nonanimated GIFs appear for about 2 seconds--then flip to the next ad.

Granted, I have rather unusual browser settings--0 cache, always update 
pages--so that I can be sure that on those local iterations I'm never 
seeing a previous version of CSS or text or graphics, etc. But this IS 
rather disturbing. Is there any way to make this an on-load-only function? 
Do I have to do it client-side to keep this from happening?

--Steve