You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am David Smith, I want to go for a holiday trip to Houston to visit some famous places.

ASSISTANT: Ok.

USER: Will you be my helping hand in making a reservation with direct flight?

ASSISTANT: Sure, let me know your travelling dates?

USER: My journey dates are from 12/14 to 12/16.

ASSISTANT: Let me know your source and destination?

USER: My source code is CLT and destination code is HOU.

ASSISTANT: Ok, please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, no direct flight found with your requested details.

USER: It's  ok. Thanks for the response.

ASSISTANT: Thanks for approaching us.