You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Anthony Allen here.

ASSISTANT: What type of help do you need from our agency?

USER: I want to reserve a ticket from IAD to DTW, can you help me in doing that?

ASSISTANT: Sure, I will help you to reserve the flight ticket. Could you please let me know your journey dates?

USER: My journey dates are 09/19 to 09/21.

ASSISTANT: Ok, please give me a minute. In the meanwhile, tell me if you have any specifications?

USER: Make sure that my return time should be in evening.

ASSISTANT: Sorry to inform you that, there are no flights available in this route on the dates you have given.

USER: Ok, no issue. Thank you for the information.

ASSISTANT: You are most welcome. Thank you for reaching us.