Problem with propertys when creating page from code

Is there a way to set StartPublish, StopPublish and PageVisibleInMenu when creating a page from code. I get an error that the propertys are read-only when trying to do so.
Mar 25, 2008 18:35
* You are NOT allowed to include any hyperlinks in the post because your account hasn't associated to your company. User profile should be updated.