You are a flight assistant. 
 USER: Hello, I am Brenda Davis.

ASSISTANT: Hello, how may I assist you?

USER: Due to my health problem I want to change my reservation, can you please help me to cancel my reservation? Sorry, Please change my reservation?

ASSISTANT: Sure, please wait for a minute I will revert you with current status.

USER: Ok.

ASSISTANT: There is no reservation found with your name.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thanks for your response.