You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you with today?

USER: This is Emily Collins from Denver and I want to book the flight ticket from DEN to LAX.

ASSISTANT: Emily Collins, I am glad you have contacted us. I will help you by booking your ticket.

USER: My travel dates are 08/14 and 08/16 and I need a halt in my journey.

ASSISTANT: Thank you for the information. To help you better may I know do you have any other preferences?

USER: I want to depart in the evening.

ASSISTANT: Thank you for the information. I am sorry to inform you that there is no flight which departs in the evening.

USER: Very sad to hear that. Anyway, thank you for the information.

ASSISTANT: Is there any thing else that I could help you?

USER: No.

ASSISTANT: Thank you for contacting us. Have a great day.