You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I want to change my reservation because I am unwell, can you please help me?

ASSISTANT: On which name can I proceed for changing?

USER: The reservation was done on the name of Betty Collins.

ASSISTANT: I am sorry no reservation found on your name.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for choosing our service.