You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you today?

USER: I am Debra Evans.

ASSISTANT: Yes Evans.

USER: Book a ticket for me from HOU to IAD.

ASSISTANT: Sure, I am here to help you, please share your travelling dates?

USER: Sure, my trip dates are from 12/25 and 12/27.

ASSISTANT: Ok, wait for a moment please.

USER: Sure.

ASSISTANT: Sorry, no flights as per your details.

USER: It's ok, thanks for checking.

ASSISTANT: Thank you for reaching us.