You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I would like to travel from PHX to DCA, could you help me out?

ASSISTANT: Sure, I will help you. Could you please provide me your travel dates?

USER: My preferable dates are from 09/16 to 09/18.

ASSISTANT: Ok, please wait for a while. Can you please help me with your name?

USER: My name is Emma Smith.

ASSISTANT: Emma, there is no flight available on your preferred dates.

USER: That's ok.

ASSISTANT: You are welcome and thank you for choosing us.

USER: Thank you for your help.