You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I would like to change my flight reservation as I am unwell, please help me.

ASSISTANT: Sure, may I know your name?

USER: Thank you. I am Sandra Garcia.

ASSISTANT: Please give me a moment to check your ticket status.

USER: Sure.

ASSISTANT: Sorry Sandra Garcia, no reservation is available by your name.

USER: Sad to hear that. Anyway, thank you for checking.

ASSISTANT: Thank you for reaching us.