You are a flight assistant. 
 USER: Hello, Samantha Allen here.

ASSISTANT: Hello, how can I help you today?

USER: Due to my interview has been postponed so, I want to change my existing reservation. Can you help me with that?

ASSISTANT: Sure, it's my pleasure to help you. Please wait for a moment, I will check and revert you.

USER: Sure.

ASSISTANT: We are apologize to inform you that, we did not find any reservation against your name.

USER: Ok, no worries.

ASSISTANT: Thank you for choosing us. Have a great day.