You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Christopher Smith here.

ASSISTANT: How can I assist you?

USER: I want to reserve my ticket from DTW to LAS, can you please help me?

ASSISTANT: Sure Smith, can I know the travel dates please?

USER: Sure, my preferable dates of journey are from 11/24 to 11/26.

ASSISTANT: Ok, wait a moment please.

USER: Sure.

ASSISTANT: Sorry, there are no flights available on your route.

USER: Ok, no problem.

ASSISTANT: Thank you for approaching us.

USER: Anyways, thank you for your service.