You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you out?

USER: I am Jeffrey Campbell want to visit OAK, can you book a ticket from DFW?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: Sure, my travelling dates will be 07/18 and 07/20.

ASSISTANT: Sorry, there are no flights found.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.