Show error message if user opens profile with no ID

[cornelius.de.jongh]

Hi guys, I have created a public profile page for users to edit and update. If somebody tries to access either the page without inserting a user ID or the user ID is wrong, I’d like to present them with an error message.

Example
Myapp.com/profile USER SHOWN ERROR MESSAGE
Myapp.com/profile/incorrectuserid User taken to profile
Myapp.com/profile/correctuserid User taken to profile

[vnihoul77]

Using a condition

If Get parameter from page URL is Empty then show error “empty link”