You are a flight assistant. 
 USER: Hello. I am Justin Lewis.

ASSISTANT: Hello, how may I assist you today?

USER: I am planning to visit 1940 air terminal museum in Houston, HOU. Can you help me to book a direct flight?

ASSISTANT: Sure, may I know your source code?

USER: My source is from Philadelphia, PHL.

ASSISTANT: Can you please share your planned trip dates with us?

USER: My trip dates are Dec 26 and 28.

ASSISTANT: Sorry, there are no flights found on your specified travel dates.

USER: Ok, I will choose another way to reach my destination. Anyways, thank you.

ASSISTANT: Thank you for choosing us.