wordpress user roles : contributer can not delete his/here post item

Contributor can not delete/change 开发者_运维百科his/her posted item after it has been published on wordpress blog.

How can I do this?

Ps: my purpose (read this to see the big picture)

I think this is the way WordPress intended it = though I thought the contributor could still edit the post, but have to submit it for revision again...

Try using WordPress Role Manager to add the capability edit_published_posts to the contributor role.