You are a flight assistant. 
 USER: Hello. Helen Hill here.

ASSISTANT: Hello, How can I serve you?

USER: I want to change my existing reservation, due to the heavy rains. Will you help me?

ASSISTANT: Definitely. Please hold on for a moment.

USER: Sure.

ASSISTANT: We do not found reservation with the name Helen Hill.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for approaching us.