You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Mark Hernandez.

ASSISTANT: How can I assist you today?

USER: I want to attend an event in San Francisco. Can you help me to book a ticket from SEA to SFO?

ASSISTANT: Sure, can you please share your travel dates?

USER: I want to travel on 03/21 and 03/23.

ASSISTANT: Ok, let me check for the availability of flight.

USER: Ok, take your time.

ASSISTANT: Mark, I am sorry to inform you that there is no flight available at your request.

USER: That's ok. I will find another way to reach there.

ASSISTANT: Thank you for opting us.

USER: Thank you for your help.