You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hi. How can I assist you?

USER: Unfortunately, I want to change my existing reservation which is done recently due to some health issues, can you please help me in this?

ASSISTANT: Sure, can you please let me know your name to check the reservation status?

USER: Ok, please check it under the name as Nicholas Robinson.

ASSISTANT: Ok, wait a moment please.

USER: Sure, take your time.

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

USER: Ok, no problem. I will try with the another travelling agency.

ASSISTANT: Thank you for approaching us.

USER: Anyways, thank you for your service.