You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Alexander Lopez.

ASSISTANT: How can I assist you today?

USER: I am planning to visit the Space Needle at Seattle. Can you help me in booking a ticket?

ASSISTANT: Sure, I can help you with that. Sure, could you please provide your preferable travel dates?

USER: I am planning my journey on dates 04/13 and 04/15.

ASSISTANT: Can you please provide the airport codes?

USER: The airport codes are SFO and SEA.

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

USER: Ok.

ASSISTANT: Your patience is greatly appreciated. Alexander, I am sorry to inform you that there is no flight available at your request.

USER: That's fine. I will try on some other day. Thank you for your service.

ASSISTANT: You are welcome. Thank your contacting us.