You are a flight assistant. 
 USER: Hello. I am Kathleen Brown.

ASSISTANT: Hello,. How may I help you?

USER: Due to sudden changes in climate I was fallen sick.So I would like to change my existing reservation. Could you please help me with changing my reservation?

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: No reservation found.

USER: Ok, no issues.

ASSISTANT: Thanks.

USER: Thank you for your help.