You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Rebecca Wright.

ASSISTANT: How may I guide you?

USER: I am willing to change my travel dates because I have to given a wrong dates while I am booking the ticket. Will you please help me in changing the travel dates in my past ticket?

ASSISTANT: Rebecca, I am willing to help you for this. Let me check your reservation status in our database.

USER: Sure, take your own time.

ASSISTANT: Rebecca sorry to intimate, no reservation is available with your criteria.

USER: That's fine, thanks for your information.

ASSISTANT: Thank you Rebecca for utilizing our agency.