You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: Owing to an emergency, my FIFA tournament rescheduled to future dates. So I need to change my existing reservation, can you help me with that?

ASSISTANT: Sure, may I know your name to check in the reservation list?

USER: Sure, I had a recent reservation with name Dennis Miller.

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

USER: Ok, no worries at all.

ASSISTANT: Thanks for opting us.

USER: I appreciate your quality service.