I'm doing the oauth dance with foursquare's api and upon exchanging my request token for an access token I am redirected to an unexpected screen. The screen asks the user to "return to myapp and use this access code to complete the authorization process: WQJITL". Is the reason I am receiving this screen because of a missing header or something; shouldn't foursquare authorize the user at once and return an access token without any questions asked of the user? What is a user supposed to do with the access code at my app to complete the authorization process?