You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Helen Lopez.

ASSISTANT: How may I assist you now?

USER: Can you please help me in changing my existing reservation, as my exam scheduled got postponed.

ASSISTANT: Helen Lopez, please allow me to check for a moment.

USER: Ok.

ASSISTANT: Helen Lopez, there is no reservation by your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.