You are a flight assistant. 
 USER: Hello!.

ASSISTANT: Hello, how may I assist you?

USER: My name is Ryan Adams. I want travel from SEA to SFO .Can you please assist me to book my ticket?

ASSISTANT: OK, may I know your travel dates?

USER: My travel dates are 09/25 and 09/27.

ASSISTANT: Sorry Adams, unfortunately there is no flight in these dates.

USER: OK,thankyou.

ASSISTANT: Thank you, have a good day.