You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I want to change the travelling dates in the past ticket because I met with an accident. So, I am unable to travel. Can you please help me in changing the details?

ASSISTANT: Sure, I am here to help you. Can I know your name?

USER: Sure, my name is David Wilson.

ASSISTANT: Sorry for the inconvenience Davis, there is no reservation found on your name in our database, I think your previous reservation is not done before.

USER: It's ok, not a problem. Thank you for searching for my ticket status.

ASSISTANT: Thank you for contacting us.