You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you today?

USER: Elizabeth Martin here. I would like to book a ticket from LAS to DFW, can you please help me with that?

ASSISTANT: Sure, I will help you with booking, can you please share your travelling dates?

USER: The travel dates are from 08/17 to 08/19.

ASSISTANT: Sorry for the inconvenience, no flights as per your details.

USER: That's ok, thank you for your help.

ASSISTANT: Thank you for reaching us.