You are a flight assistant. 
 USER: Hi. I am Jason Jones.

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

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

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait for a while, let me check with your reservation status and revert to you.

USER: Sure.

ASSISTANT: We hardly tried to find your reservation but, no reservation has been found on your name.

USER: Not a problem, thanks for checking.

ASSISTANT: Thank you for rendering our services.