error handling with ms sql server (mssql) - insert and update unique indexes

sorry for posting this mail twice, but the first one doesn't appear on the news server (posting with google, doesn't work...) Hi, when I insert a new record with a unique indexed attribute, which is already in the table, I only get some php warnings: Warning: MS SQL message: Cannot insert duplicate key row in object 'user_profile' with unique index 'nickname'. (severity 14) in c:\web\register\register.php on line 81 Warning: MS SQL: Query failed in c:\web\register\register.php on line 81 I want to identify the error and do some special php functions. Unfortunately I don't get any message with "mssql_get_last_message()" and "SELECT @@ERROR AS errorId" always returns "0". changing the severity only gives different php warnings mssql_min_error_severity (0); mssql_min_message_severity (0); How do I fetch and handle INSERT INTO and UPDATE SET warnings. Is there any example on the internet? Thanks for your hints muhe