[Sa Li El]

If you're talking about forum posts, then you are really asking this in the wrong place. But, to delete your forum posts, you click on the Edit button of the post, then you click on Go Advanced. At the top, there is a radio button that you fill in to "Delete Message", then click the "Delete this Message" button. Though, I don't know why it's really that important to delete your posts, even if they are a bit foolish.

Also, maybe because it would delete the whole thread and take away people's posts, you can't delete your post if it is the first post in the thread (if you started the thread). Although, perhaps it's possible if no one replied.