note 41757 rejected from function.mysql-free-result by betz

Note Submitter: radicadoenmiami@hotmail.com ---- Hi, I have this code: // When function is invoked by a Dynamically set Site, then clear on-line table $result = mysql_query( "select staticupdate from $prefix"._msanalysis_admin." where id='1'" ); list( $staticupdate ) = mysql_fetch_row( $result ); if( ! $staticupdate ) { // Delete all records from table msanalysis_online mysql_query( "OPTIMIZE TABLE $prefix"._msanalysis_online); $result = mysql_query( "DELETE QUICK FROM $prefix"._msanalysis_online); mysql_free_result($result); mysql_query("OPTIMIZE TABLE $prefix"._msanalysis_online); } } And when I run it it gives me the following error: Warning: mysql_free_result(): supplied argument is not a valid MySQL result resource in /path/to/root/file.php on line 319 Does anybody know what is the reason of this error? Thank you.