You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: Virginia Collins here. I want to change my reservation due to health issues, can you help me?

ASSISTANT: Sure, I will help you with that.

USER: Ok, I will be waiting for your response.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: Oh! That's very sad to know, thank you for checking anyways.

ASSISTANT: Thank you for contacting us.

USER: Most welcome.