You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Stephanie Baker.

ASSISTANT: How may I assist you today?

USER: Can you please book a flight ticket from LGA to IAH?

ASSISTANT: Sure, may I know your travel dates?

USER: Sure, I need to travel on dates of 12/11 and 12/13.

ASSISTANT: Sorry, I could not find any flight with your travel dates.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: My pleasure.