You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Can you please help me in reserving a flight ticket to PHX from DCA?

ASSISTANT: Sure, please provide your trip dates.

USER: My preferred dates of travel are from Aug 25 to Aug 27.

ASSISTANT: Do you have any specifications?

USER: Yes, I need a flight with single connection.

ASSISTANT: May I know your name?

USER: I am Michael Lopez.

ASSISTANT: Which class do you prefer?

USER: I am comfortable with any class.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Sorry Michael Lopez, no flights are available on your route.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.