You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Susan Mitchell here.

ASSISTANT: Nice to meet you Susan.

USER: I want to change my existing reservation due to my grand father health, will you help me on that?

ASSISTANT: Sure Susan, give me a moment.

USER: Sure.

ASSISTANT: Sorry to say this Susan, we could not find a flight ticket under your name.

USER: Ok, That's fine. Thank you for your response.

ASSISTANT: You are welcome. Have a good day.