You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: William Jackson here.

ASSISTANT: How can I help you today?

USER: Can you help me with booking ticket from LAS to EWR, to meet my parents.

ASSISTANT: Please share your trip dates.

USER: Ok, my travelling dates are from Apr 18 to 20.

ASSISTANT: Do you need any connection limit?

USER: I need a connecting flight and I want to departure in the afternoon time.

ASSISTANT: May I know your class preferance?

USER: I am ok with any class.

ASSISTANT: Sorry to inform you, there are no available flights found on your name.

USER: It's ok, thanks for checking.

ASSISTANT: Thank you for choosing us.