Progress indicator page and back button problems

How to prevent back button causing duplicate searches

[limitup]

We offer a search service that queries millions of records and sometimes takes 5-20+ seconds to complete. So the way it's setup now is that when someone submits a search, a "progress indicator" page loads which shows the user the search is taking place, and then when the results are available it refreshes to the results page.

The problem is that many many people hit their back button in an attempt to return to the search page and do another search. The problem is that when you hit the back button it simply goes back to the "progress indicator" page and redoes the same search. This is not what they want, and puts a huge amount of extra stress on our servers for no reason.

Oddly enough I can't figure out the way around this from a technical perspective. Yes we can put something on the results page that says CLICK HERE TO DO ANOTHER SEARCH but we all know people love to hit their back button.

What am I missing here? Surely there's an easy way to deal with this?

[zomega42]

You could use javascript's location.replace to do the redirect. Unlike location.href, this will eliminate the current page (the progress bar) from the browser's history, so when they hit back it will go back to the search form.