You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Debra Wilson here.

ASSISTANT: How can I assist you today?

USER: Please help me out in booking the ticket from LAS to HOU.

ASSISTANT: Sure, I can help you with that. May I know your preferable travel dates please?

USER: Sure, my trip dates will be 04/28 to 04/30.

ASSISTANT: Ok, please wait for a while.

USER: Sure, I will wait.

ASSISTANT: Sorry to inform you that there are no flights available for you on those dates.

USER: That's ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.