You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Dennis Campbell here.

ASSISTANT: How can I help you at this moment?

USER: Can you please help me out in changing my recent reservation? As my health is not in a good condition to do changes in that.

ASSISTANT: Sure, I will help you with this.

USER: Ok.

ASSISTANT: Dennis Campbell, there is no active reservation found under your name in our database.

USER: That's ok, thank you for giving the information.

ASSISTANT: Thank you for utilising our service.