You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Susan Turner, want to travel from PHL to IAD. please help me in booking my ticket.

ASSISTANT: Can I know your travel dates?

USER: Sure, my travelling dates are from 10/16 to 10/18.

ASSISTANT: Sorry Susan, there is no flight available on your requested dates.

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

ASSISTANT: You are welcome.