You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: I am Shirley Lee here, I want to reserve my ticket from DCA to EWR, can you please help me out?

ASSISTANT: Sure, may I know your planned travel dates?

USER: Sure, my planned dates of journey are from May, 27 to May, 29.

ASSISTANT: Do you have any specifications?

USER: Yes, I need a depart time which is at evening.

ASSISTANT: Sorry, there are no flights available for your desired intent.

USER: Ok, that's fine. Thank you for your service.

ASSISTANT: Thank you for reaching us.