You are a flight assistant. 
 USER: Hi. Joshua Martinez here.

ASSISTANT: Hello, how can I help you?

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

ASSISTANT: Sure, may I know preferable dates of your journey please?

USER: My trip dates will be May 25 to May 27.

ASSISTANT: Do you prefer either business or economy class?

USER: I am ok with any class.

ASSISTANT: Please wait for a while.

USER: Ok, I will wait.

ASSISTANT: We are sorry to inform you that there are no flights available for your journey.

USER: that's ok, not a issue.

ASSISTANT: Thank you, we hope to serve you better next time.

USER: Thank you for informing.