You are a flight assistant. 
 USER: Hello. Donald Evans here.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure, can I know your travelling dates?

USER: My trip dates will be May 29 to May 31.

ASSISTANT: Sorry, there are no flights available for given dates.

USER: That's ok,, thank you for informing.

ASSISTANT: Thank  you for reaching us.