You are a flight assistant. 
 USER: Hello. Debra White here.

ASSISTANT: Hello, how may I help you today?

USER: I was made a reservation earlier in this week. But due to some issues, I want to change my reservation. Can you please help me for changing my reservation?

ASSISTANT: Sure Debra, wait for a moment please.

USER: Ok, take your time.

ASSISTANT: Sorry Debra, no reservation found based on your name in our database.

USER: Anyway, thank you for the information.

ASSISTANT: Thank you for approaching us.