Hi Somar, once someone replies to your post (or you edit it), it can't be deleted. If you see a delete button in edit mode, you can try that, although it doesn't seem to work very well. You'd only be able to delete your own post in any event, and not those of someone else.
If you have a good reason for wanting the post gone, you could write to the forum moderators (check the contact information under "Magazines"). They should have the capability to remove (or hide it) from view. I hope this helps. Rhonda