You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I have to meet my business partner at Los Angeles, can you please book the flight ticket from DEN to LAX?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Can you please provide your preferable dates of travelling?

USER: I want to depart on 12/24 and also book the return ticket on 12/26.

ASSISTANT: On whose name I have to book the flight ticket?

USER: Please book on the name of David Hall.

ASSISTANT: Please be on hold to check the flights. Sorry to inform you that, there are no flights found with your planned dates of travelling.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for reaching us, have a great day.