Those META tags will often, but not always, be respected. No agent is forced to respect them to be compliant with HTTP standards. Better to include these in the HTTP header directly, right by your 'Content-type' line. If you are using CGI::Simple or similar (and you really should be):

print $cgi->header( -expires => 0, -nph => 1, -type => 'text/html' );
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If you aren't using one of the CGI modules (again, you probably should be), you can also do:

print "Expires: 0\n";                # Expire immediately
print "Pragma: no-cache\n";          # Work as NPH
print "Content-type: text/html\n\n"; # <- mentioned as context
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Any valid HTTP/1.1 (or higher) client will respect these headers as expiring in the past, and therefore require a reload the next time the page is viewed.