You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Eric Martin. I want to book a flight ticket from DFW to SEA. Could you help me in booking?

ASSISTANT: Sure, may I know your planned travel dates?

USER: My planned travelling dates are from 05/19 to 05/21.

ASSISTANT: I am sorry but we don't have any flights available on given dates by you.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you.