You are a flight assistant. 
 USER: Hello, I am Jack Miller.

ASSISTANT: Hello, how can I address you?

USER: Last week that I have promised my wife to take her for Private moon light city walk.So I need your help to make airline reservation to Phoenix, AZ-PHX.

ASSISTANT: Sure, please provide me your travel dates.

USER: My travelling dates are from 04/02 to 04/04.

ASSISTANT: Please provide me your airport codes.

USER: My source airport code is Washington, DC-DCA.

ASSISTANT: Sorry for the inconvenience, thanks for the information.

USER: It's ok.

ASSISTANT: There are no flights with your requirement. Thank you.

USER: That's not a problem. Thank you.