You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Robert Evans here.

ASSISTANT: How may I help you at this moment?

USER: I want to change my  reservation due to my health issues. Can you please help me?

ASSISTANT: Sure, I am here to help you with that.

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

ASSISTANT: Please wait for a minute.

USER: Ok, I am waiting.

ASSISTANT: Sorry to say that, there is no reservation found based on your name in our database.

USER: Oh! That's fine, thank you for checking anyways.

ASSISTANT: Thank you for reaching us.

USER: You are most welcome.