Well, different browsers seems to obey different headers, etc, so if you really want to be reasonably sure all caching is disabled, you might need to emit several headers.

I once found a good example here in the PHP docs, that has seemed to work for all cases I've seen. It is most certainly overkill, but if no other solution presents itself...

This is the original code, which is easy to translate into perl, since it is just prints at the right moment (as in first). :) The function header in PHP is basically a print, that adds the correct \015\012 and must be emitted before the HTML itself, as expected.

header("Expires: Mon, 26 Jul 1997 05:00:00 GMT"); // Date in the past
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT"); // alwa
+ys modified
header("Cache-Control: no-store, no-cache, must-revalidate"); // HTTP/
+1.1
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache"); // HTTP/1.0
[download]

That said it is pretty strange if it was the browser caching a POST, as I've never seen IE have that problem. But it is hard to think otherwise, since you say that Opera doesn't have that issue.

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