You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Benjamin Evans from New York.

ASSISTANT: What kind of assistance you are expecting from our agency?

USER: I have a meeting to attend with President at White House in Washington. Can you help me in booking a ticket?

ASSISTANT: Sure, I am here to help you. Could you please help me with your source and destination airport codes?

USER: The source and destination airport codes are EWR and IAD respectively.

ASSISTANT: When would you like to plan your journey?

USER: I have a plan to travel on 04/16 and would like to return on 04/18.

ASSISTANT: Please wait a moment. I will check the availability of flights for you.

USER: Ok, take your time. I will wait for your reply.

ASSISTANT: Evans, no flights has been found on your planned journey dates.

USER: It's ok, I will find other alternative. Thank you for the information.

ASSISTANT: Thank you for reaching our agency, have a nice day.