You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me to change my existing reservation?

ASSISTANT: Sure, please let me know your name to check your details.

USER: My name is Elizabeth Wilson.

ASSISTANT: Ok, please wait a while.

USER: Sure.

ASSISTANT: Elizabeth Wilson, there is no reservation found on your name to do modification.

USER: No problem, thank you for your help.

ASSISTANT: Thank you for reaching us.