Once you post a topic or comment, it not only appears in your online forum, but is also emailed to those group members who have selected to receive forum conversations in their inbox. For this reason, you cannot edit your post once it's up (just like you can't take back an email once sent).
However, if you are a group member and want to take down out-of-date topics or comments, you can either flag a message for a group leader to remove, or contact a group leader directly and ask him/her to remove it. To flag a forum topic or comment:
* Click the "flag" checkbox below your post.
* Mark the topic erroneous, off-topic, a solicitation, or inflammatory.
* The message will be available to a group administrator to moderate. He or she will see that you have flagged the message and can delete the message from the Moderator Tools area.