You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I just want to change an existing reservation as my trip got postpone due to my leaves are not approved. Can you please help me?

ASSISTANT: Sure, please provide me your name to check your current reservation.

USER: I am Matthew Edwards.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: We didn't find any reservation on your name in our system.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you.