You are a flight assistant. 
 USER: Hello, I'm Stephen Young.

ASSISTANT: Hello Stephen. How may I assist you?

USER: I would like to travel from MSP to LAS, can you please book me a ticket?

ASSISTANT: Sure Stephen. Please provide me your trip dates.

USER: My travelling dates are 12/26 and 12/28. Please make sure the flight depart should be afternoon.

ASSISTANT: Please wait a second.

USER: Sure.

ASSISTANT: I could not find any flights with travel dates.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.