You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Please help me in booking flight ticket from LAX to LGA.

ASSISTANT: Is there any airline preference?

USER: No.

ASSISTANT: Can I know your travelling dates?

USER: My trip dates are Aug 15 to Aug 17.

ASSISTANT: Do you have any preference?

USER: My return should be in the evening.

ASSISTANT: Let me know your name.

USER: Brenda Scott here.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you.