You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I need you to book a flight ticket from IAD to OAK. Please help me.

ASSISTANT: Sure, I am here to help you for this. When are you planning your trip?

USER: May 17 and 19 are my planned travelling dates.

ASSISTANT: May I know your name please?

USER: My name is Jennifer Davis.

ASSISTANT: Is there is any other specifications regarding your journey?

USER: I wish to depart in the afternoon.

ASSISTANT: Sorry for inconvenience, no flights are found with your specifications.

USER: That's ok. Thank you.

ASSISTANT: Thank you very much for approaching our agency.