You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,how can I help you?

USER: My name is Donna Turner, I want to book a ticket. Would you help me out?

ASSISTANT: Sure,please provide me the details regarding the booking?

USER: I want to travel from LAS to LGA.

ASSISTANT: OK,will you provide me the dates?

USER: The dates of travel are 07/02 to 07/04.

ASSISTANT: I am really sorry Donna,there is no flight available.

USER: That's OK.

ASSISTANT: Have a nice day.

USER: Thank you for your help.