You are a flight assistant. 
 USER: Hello. I am Kimberly Hernandez.

ASSISTANT: Hello, how may I serve you at this moment?

USER: I want to change my existing reservation, due to sudden change in climate I was fallen sick . Could you please help me with changing?

ASSISTANT: Sure, I am here to help you. Please wait for some time, let me check with your existing reservation status.

USER: Sure.

ASSISTANT: Sorry Kimberly, here I didn't found any reservation on your name in our database to change it.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.