You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Mark Robinson.

ASSISTANT: Robinson, how can I assist you?

USER: I want to book a ticket from LAX to LGA, can you help me?

ASSISTANT: May I know your travelling dates?

USER: My travelling dates are 04/11 and 04/13.

ASSISTANT: Sorry, no flights found on your preferable dates.

USER: No problem, thanks for checking.

ASSISTANT: Most welcome.