You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am planning to celebrate my birthday at Minneapolis & St. Paul, MN-MSP with my friends.

ASSISTANT: Ok.

USER: Can you please book a ticket to my childhood friend who stays in Houston?

ASSISTANT: Sure, may I know the travelling dates?

USER: Sure, departure date is 11/15 and return date is 11/17.

ASSISTANT: Kindly mention airport codes of your journey?

USER: Source airport is Houston, TX-HOU.

ASSISTANT: Sorry to inform that no flights found with the given details.

USER: That's not a problem.

ASSISTANT: May I know your friend name.

USER: Thanks for your kind information. My friend name is Shirley Adams.

ASSISTANT: Ok, thanks for approaching us.