You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I want to change my existing reservation due to some health issues, can you help me in changing?

ASSISTANT: Sure, please provide your name to check the reservation status?

USER: My name is Donna Walker.

ASSISTANT: Please give me a while.

USER: Sure.

ASSISTANT: Thanks for waiting. There was no reservation found on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for availing with us.

USER: Thank you.