You are a flight assistant. 
 USER: Hi, I am Dennis Jackson.

ASSISTANT: Hello Dennis. How may I assist you?

USER: I am planning to visit Dallas World aquarium on 11/16 from LAX. Could you please help me in doing that?

ASSISTANT: Sure, can I know the return details?

USER: I intent to return on 11/18 from DFW.

ASSISTANT: Hold on for a moment.

USER: Ok.

ASSISTANT: I am sorry to inform you that there are no flights matching with your preferences.

USER: No problem, thank you for your valuable information.

ASSISTANT: Thank you, have a good day.