You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: Brian Rodriguez here. I want to book a flight on the route from LAS to DTW, can you help me?

ASSISTANT: Sure, Please help me with your travel dates.

USER: My travelling dates for the following journey are from 09/07 to 09/09.

ASSISTANT: Please wait a minute.

USER: Sure, I am waiting.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Ok, please book it for me.

ASSISTANT: Thank you for choosing us.

USER: Oh! That's sad to know, thank you for checking. Most welcome.