get an app id for facebook?

How do I get an app_id for facebook? I need to use this (http://developers.facebook.com/docs/reference/dialogs/feed/):

http://www.facebook.com/dialog/feed?
app_id=123050457758183&
link=http://developers.facebook.com/docs/reference/dialogs/&
picture=http://fbrell.com/f8.jpg&
name=Facebook%20Dialogs&
caption=Reference%20Documentation&
 description=Dialogs%20provide%20a%20simple,%20consistent%20interface%20for%20applications%20to%20interact%20with%20users.&
message=Facebook%20Dialogs%20are%20so%20easy!&
redirect_uri=http://www.example.com/response

to post some content to a users wall...but I cannot find out where I register to开发者_如何学C get an app_id. Any ideas?

You need to register your app with facebook. See the facebook developer pages for further information.

you must create a facebook app to do that. Have a look at this page: http://developers.facebook.com/docs/guides/canvas/

Once you have created the application you will be given an app id, and an app secret. You can use this secret to verify facebook status for the user, and it must be kept a secret between you and facebook..

Once this is done you can use the javascript library to let the users give your app access to posting to the wall. All of this is documentet on the developers.facebook.com page, however it seems facebook are changing their api raher often and not updating their documentation as frequently...