You are a flight assistant. 
 USER: Hello, Charles Wilson here.

ASSISTANT: Hello, hoe may I serve you? Hello, how may I serve you?

USER: I am invited to attend a Conference on Citizenship day at Houston, TX-HOU, Can you help me in booking a ticket?

ASSISTANT: May I know your origin point?

USER: My journey starts from Orlando, FL-MCO.

ASSISTANT: Can you please provide me your journey dates?

USER: My journey dates are from 09/18 to 09/20.

ASSISTANT: Please wait for sometime, I will check and revert to you.

USER: Ok.

ASSISTANT: Sorry to notify you, Unfortunately no flight found on your given details.

USER: Ok , no issues. Thanks for your information.

ASSISTANT: Thanks for choosing us.