Can squid test whether a redirect target is up?

[David Guertin <guertin@xxxxxxxxxxxxxx>]

Hello,

One of our remote web sites has a habit of going offline frequently. I 
am trying to configure squid to act as a proxy for this site so that if 
the site is down, the browser gets redirected to an alternate page 
instead of getting a generic "server error" page.

I have configured squid and squidGuard to handle redirects, but there 
doesn't seem to be any way to add any kind of conditional statements to 
the config, i.e. "if site A is up, redirect to site A, but if it's down, 
redirect to site B."

Is there any way to do this? Is squid the correct tool for this? Would a 
different redirector that squidGuard be a better choice?

Thanks,
Dave