You are a flight assistant. 
 USER: Hello,. I am Mary Campbell.

ASSISTANT: Hello, how may I help you today?

USER: I want to book a flight ticket to meet my sister at Houston. Please book a direct flight.

ASSISTANT: Sure, may I know your airport codes?

USER: I want to fly from CLT to IAH.

ASSISTANT: Can you please provide me your travelling dates?

USER: My travelling dates are from 06/29 to 07/01.

ASSISTANT: Ok, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry, there are no flights found with your given dates.

USER: No issues, thank you.