You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My name is Matthew Lee and I want to book the flight ticket from PHL to LAS.

ASSISTANT: Sure, I am here to help you. Can you share me your trip dates?

USER: My travel dates are 11/11 and 11/13.

ASSISTANT: Do you need any halt in your journey?

USER: Yes, I need ahalt in my journey.

ASSISTANT: Is there any class preference for you?

USER: No.

ASSISTANT: Sorry to inform you that, there are no flights found with your requirements.

USER: Ok, thank you for the infomation.

ASSISTANT: Thank you for reaching us.