You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am Ryan Williams. Due to some emergency work, I need to change my existing reservation. Can you please help me in doing that?

ASSISTANT: Sure, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, we found no reservation with your name.

USER: It's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for reaching us.