Error on no.php.net

When i go to Quick Function Reference and just press GO without inputting any text, I get this output : Warning: Failed opening 'configuration.inc' for inclusion in /usr/local/apache/phpweb/search.php on line 51 Warning: Cannot add more header information - the header was already sent (header information may be added only before any output is generated from the script - check for text or whitespace outside PHP tags, or calls to functions that output text) in shared.inc on line 318 Warning: Cannot add more header information - the header was already sent (header information may be added only before any output is generated from the script - check for text or whitespace outside PHP tags, or calls to functions that output text) in shared.inc on line 319 Might be nice to know :) Geir.