You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you at this moment?

USER: I am Rachel Martin, want to alter my recent reservation due to some emergency. Please help me out with that.

ASSISTANT: Sure, I will help you. Please wait for a while.

USER: Thanks and sure, take your time.

ASSISTANT: Sorry, there is no reservation existing on your name.

USER: It's ok, thank you for your help.

ASSISTANT: You are welcome, thank you for reaching us. Have a nice day.