delete ONLY the actice user´s posts from mysql

I have a user in a forum application logged in with $user_name and $password set in a login page. Now I want to allow him to admin his posts: 1. see all his posts 2. edit 3. delete only HIS posts. The following code only brings an error on line 102: ... //first I find out his id from table user line 100: $active_user_id = mysqlquery("mydatabase","SELECT id FROM user WHERE user_name='$username' AND password='$password'"); // next I use the id from user to select all posts of this user // the table posts of course has a field user_id line 101: $result = mysqlquery("mydatabase","DELETE FROM posts WHERE id=$par AND user_id == $active_user_id"); line 102: $num = mysql_numrows($result); /* Simply wont work I GET AN ERROR MESSAGE FOR THE LINE 102 THOUGH THERE ARE RECORDS IN THE DATABASE */ ... Any idea around? Helmut