You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Melissa Edwards, want to travel from IAD to EWR. Please help me in booking my ticket.

ASSISTANT: Sure, on which dates you are planning to travel?

USER: Sure, my trip dates are from 11/08 to 11/10.

ASSISTANT: Sorry, on these dates there is no flights available.

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

ASSISTANT: Most welcome.