You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I benefit you?

USER: Gregory Harris here. I would like to book a ticket from PHL to IAD, can you please help me with that?

ASSISTANT: Sure, on what dates are you planning to make your trip.

USER: The travel dates are from 08/05 to 08/07.

ASSISTANT: Ok, please wait.

USER: Ok.

ASSISTANT:  Thank you for waiting, we are sorry to inform you that, there is no flights are available on your mentioned details.

USER: That's ok, thank you for your help.

ASSISTANT: Thank you for reaching us.