$query = "INSERT INTO table1 (name, comment, age) VALUES ('$name', '$comment', $age)";

When building the above SQL statement with magic quotes turned on and set to sybase style
the fellowing happens.

If $comment contains a double quote or a back slash the string $query will evaluate to
"INSERT INTO table1 (name, comment, age) VALUES ('$name', '$comment'"
Otherwise it will evaluate to the expected
"INSERT INTO table1 (name, comment, age) VALUES ('$name', '$comment', $age)"

for example if the values posted from the web are as follows.
$name = "jo bob"
$comment = "My favorite quote "work is fun" is not representative of how I feel today"
$age = "33"

The resulting string $query will be
"INSERT INTO table1 (name, comment, age) VALUES ('jo bob', 'My favorite quote "work is fun" is not representative of how I feel today"
But it should be
"INSERT INTO table1 (name, comment, age) VALUES ('jo bob', 'My favorite quote "work is fun" is not representative of how I feel today', 33"