You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I need to change my existing my reservation due to some health issues I  am unable to catch the flight, can you help me in changing my ticket?

ASSISTANT: May I know your name?

USER: My name is Joshua Rodriguez.

ASSISTANT: Please wait for a moment.

USER: Ok.

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

USER: It's ok, thank you for searching.

ASSISTANT: You are welcome. Thank you for reaching us.