You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I would like to visit Detroit, can you help me out in booking a flight ticket from IAH to DTW.

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: My preferable dates are 04/20 and 04/22.

ASSISTANT: Can I know your name please?

USER: I am Kathleen Clark.

ASSISTANT: Sorry, there are no flights found in our database.

USER: That's ok, I will contact with another service.

ASSISTANT: Thank you for reaching us.