You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I serve you?

USER: I am Elizabeth Williams. I am a science student and planning to visit one of the best museum, but due to health issues my planning to visit has been postponed.So I would like to change my existing reservation. Can you please help me?

ASSISTANT: Sure. Give me a minute.

USER: Sure, I will be waiting.

ASSISTANT: Thanks  for your time. We didn't found any reservation by this name.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thanks for approaching us.