You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how could I aid you?

USER: Can you please book a flight ticket from EWR to MCO?

ASSISTANT: Sure, can you please share me your travelling dates?

USER: My travelling dates are May 15 and May 17.

ASSISTANT: Do you have any other specifications?

USER: I want to depart in the evening.

ASSISTANT: May I know your name please for further process?

USER: My name is Elizabeth Clark.

ASSISTANT: We are sorry to inform you that there is no flight available on your route.

USER: That's ok, thank you for the response.

ASSISTANT: Thank you.