You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Donna Thomas.

ASSISTANT: How may I help you at this moment?

USER: Can you make me reservation from PHL to LAS?

ASSISTANT: Sure, I am here to help you with that. Can I know your planned trip dates?

USER: Sure, my trip dates are 12/21 and 12/23.

ASSISTANT: Let me check with the your intent in our booking site. Please wait for a minute.

USER: Ok, I will wait for your information.

ASSISTANT: Sorry to inform you that, there are no flight's found based on your journey details.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.

USER: You are most welcome.