You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know your name?

USER: My name is Edward Anderson.

ASSISTANT: How may I aid you today?

USER: As I want to attend press conference in the capital city of United States, can you please book a flight on dates 03/05 and 03/07?

ASSISTANT: Sure, may I know your airport codes?

USER: Sure, my airport codes are CLT and IAD.

ASSISTANT: Ok, please wait for a couple of minutes.

USER: Sure.

ASSISTANT: Thank you for waiting. Unfortunately there are no flights available with your requirements.

USER: Ok, no issue.

ASSISTANT: Thank you for reaching us.

USER: Thank you.