You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: Actually, I want to change my reservation which is done recently due to some problems, can you please help me?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please provide your name.

USER: Sure, my name is Elizabeth Williams.

ASSISTANT: Wait a minute please.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting, sorry we didn't find any reservation with your name.

USER: Ok, no problem. Thank you for your service.

ASSISTANT: Thank you for opting us, have a good day.