HTTP Authentication example forcing a new name/password
<?php function authenticate() { Header( "WWW-authenticate: basic realm='Test System'"); Header( "HTTP/1.0 401 Unauthorized"); echo "You must enter a valid login ID and password to access this resource\n"; exit; } if(!isset($PHP_AUTH_USER) || ($SeenBefore == 1 && !strcmp($OldAuth, $PHP_AUTH_USER)) ) { authenticate(); } else { echo "Welcome: $PHP_AUTH_USER<BR>"; echo "Old: $OldAuth"; echo "<FORM ACTION=\"$PHP_SELF\" METHOD=POST>\n"; echo "<INPUT TYPE=HIDDEN NAME=\"SeenBefore\" VALUE=\"1\">\n"; echo "<INPUT TYPE=HIDDEN NAME=\"OldAuth\" VALUE=\"$PHP_AUTH_USER\">\n"; echo "<INPUT TYPE=Submit VALUE=\"Re Authenticate\">\n"; echo "</FORM>\n"; } ?>