how to get the text inputted into a fb:friend-selector

I want to get the text from an fb:f开发者_JAVA百科riend-selector even if a friend was not selected, how cna I do this? So for example if someone enters someone who is not a friend, I want to be able to get that data. The form is submitted to my server and not facebook's

See: If the user enters a name that does not match any of his friends, idname gets set to an empty string (instead of a uid number) and name gets set to the entered text.

http://wiki.developers.facebook.com/index.php/Fb:friend-selector