You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am James Phillips, want to travel from DCA to PHL. Please help me in booking my ticket.

ASSISTANT: On which dates you are planning to travel? Do you have any depart and arrival time preference?

USER: Sure, my travelling dates are from 09/08 to 09/10. My departing time will be in the evening.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry James, there is no flights.

USER: It's ok, thank you.

ASSISTANT: Welcome.