You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: John Miller here.

ASSISTANT: How can I help you?

USER: My wedding has been postponed, so I want to reschedule my itinerary dates.

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

USER: Sure.

ASSISTANT: Sorry for inconvenience, no reservation is found with your criteria.

USER: No problem, thank you.

ASSISTANT: Thank you very much for reaching us.