Click on the "Edit" button. When your post appears look in the upper left hand corner. There you will see a green icon with the word "Done" next to it and a red "icon" with the word "Cancel" next to it. Just click on the appropriate circle and then depress the "Submit" button and you will be all done.
Beth, to follow up on what Roberta shared, you must open your original request post, not a reply to that post, and then you will see the "edit" button on the upper RIGHT top section , not the left
Once the edit opens, you will see and Topic Option above the message area that gives you a choice of DONE or CANCEL. Mark the circle next to DONE. Then scroll down below your message and click on the submit button. One of our very helpful volunteers will then move your post off the current board over to the DONE forum.