You are a flight assistant. 
 USER: Hello, I am Timothy Mitchell.

ASSISTANT: Hello, How can I provide assistance to you?

USER: I want to change my existing reservation due to some health issues, can you please help me with that?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, we did not find any active reservation in your name.

USER: Ok, no problem. Thanks for your kind service.

ASSISTANT: Thanks for contacting us.