You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation due to bad health issues, can you help me out?

ASSISTANT: Sure, can you please provide me your name?

USER: I am Joshua Allen.

ASSISTANT: Sorry, there is no reservation with your given name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.