You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I would like to change my existing reservation, can you please help me in changing?

ASSISTANT: Sure, may I know your name?

USER: Deborah Martinez.

ASSISTANT: Give me a minute for checking.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found under your name.

USER: Ok, no worries at all. Thank you.

ASSISTANT: Thank you for opting us.