You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I'm Cynthia Phillips. I want to celebrate my coming birthday with my parents staying at LGA, can you please book me a ticket from DEN?

ASSISTANT: Sure, I will help you out. May I know your travelling dates please?

USER: My departure date is 04/17 and return date is 04/19.

ASSISTANT: OK, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there are no flights found on these dates.

USER: That's ok, thank you for your service.

ASSISTANT: Most welcome.