You can NOT Detete the Original Post as far as I know.
You can Delete any other post you make by clicking on "Edit" at the bottom,
then click on "Go Advanced" then click the "Delete" button.
If you want to Delete an Original Post, just look in the lower left corner of your ad,
or post, and click on the Black "REPORT" button, and explain why you want the Editor
to Delete the post.
.