You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself William Thomas.

ASSISTANT: William, how may I guide you?

USER: Will you help me in booking the flight ticket from DTW to HOU?

ASSISTANT: Sure, I will help you for that. When you are willing to travel?

USER: My preferable journey dates are 07/08 and 07/10.

ASSISTANT: Please be on hold.

USER: Ok, I will wait for your response.

ASSISTANT: William, sorry for inconvenience, no flights is available on your prefer dates.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: You are welcome, thank you very much for contacting us.