You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Emma Miller here.

ASSISTANT: How may I assist you at this moment?

USER: Can you please help me in changing my recent reservation? As my planned trip has been postponed to some other dates.

ASSISTANT: Sure, I will help you with that. Please wait a moment to check your previous reservation.

USER: Sure, I'll wait for your response.

ASSISTANT: We regret to inform you that there is no reservation found on your name in our records.

USER: Oh! That's fine, thank you for giving the information.

ASSISTANT: Thank you for reaching us, have a great day.