Exclude category from query

try:

global $query_string;
query_posts( $query_string . '&cat=-81' );

http://codex.wordpress.org/Function_Reference/query_posts#Preserving_Existing_Query_Parameters

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)