Redirect to a different site if server/site is down

We have two OWA servers located in two different facilities. What we would
like to have our OWA users to do is to try hitting a URL [probabaly like
mail.mycompany.com] and divert them to mail1.mycompany.com or
mail2.mycompany.com randomly. If mail1 server is down, they should go to
mail2 server automatically and viceversa. Can we do this on IIS 6 without
scripting?

Our external [internet] sites are at a hosting facility and I can direct
mail.mycompany.com to go there, but I'm not aware a way of diverting users to
mail1 or mail2 servers randomly without code.

Can any of you IIS pundits help me please?