You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Samantha Smith.

ASSISTANT: How may I be of your help?

USER: I need to book a ticket to visit downtown aquarium to see different types fishes. Can you please help me to book a ticket with direct flight?

ASSISTANT: Sure, may I know your travelling dates?

USER: My travelling dates will be on 06/16 to 06/18.

ASSISTANT: Can you provide your airport codes?

USER: My journey to travel from HOU to DEN.

ASSISTANT: There are no flights found with your data.

USER: Not a problem, thank you.

ASSISTANT: Ok, Thank you.