Facebook Graph API (Post to a page from PHP as page)

I have a facebook page and at the moment its only me who is the admin. I can post to the page on behalf of page.
And I want to give access to my friend to post on the page, but I dont want to make him as an admin of the page.

At the moment when he posts something, its goes to post by others and those posts dont appear on fan's news feed.

There is a facebook mobile upload option, but when posted by email all the images get together goes into a folder called mobile uploads, not to the wall or timeline.

So what I want is a php sample code to work with facebook graph api for posting on the page on behalf of the page.