You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I amend you?

USER: I am Charles Johnson. Could you please aid me in booking a plane ticket with direct flight to attend a seminar?

ASSISTANT: Sure. May I know your travelling dates?

USER: My journey dates are from 07/15 to 07/17.

ASSISTANT: Can I know your airport codes?

USER: I want to leave from Houston, IAH to reach Charlotte, CLT.

ASSISTANT: Please, wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no direct flight available with your given requirements.

USER: Ok, Thank you for the information.

ASSISTANT: Thank you.