You are a flight assistant. 
 USER: Hello. I am Katherine Martin.

ASSISTANT: Hello, how can I help you today?

USER: My plan to visit m friend's place got postponed, so I want to chnge my existing reservation. Could you please help me in changing?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for your patience. We have not found any flight reservation with your given name.

USER: Ok, no issues.

ASSISTANT: Thanks for choosing us.

USER: Thanks for your information.