You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Brenda Gonzalez here.

ASSISTANT: Nice to meet you Brenda, how should I help you at this right time?

USER: As my sister's baby shower party is preponed, I want to change my existing reservation. Will you please help me with that?

ASSISTANT: Sure, I happy to help you with that. Please give me a moment.

USER: Ok.

ASSISTANT: Thank you for waiting. Sorry Brenda, there is no reservation under your name. Thank you for reaching us.

USER: Thank you for your information.

ASSISTANT: You are welcome, have a good day.