You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: My name is Donald Moore. Owing to emergency, I need to change my recent reservation. Please help me in that.

ASSISTANT: Ok, I will help you with that.

USER: Thank you.

ASSISTANT: Ok, please allow me a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation with your name in our portal to make changes.

USER: No problem, thanks for your information.

ASSISTANT: You are welcome, have a great day.