You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Sandra Robinson here.

ASSISTANT: How can I help you Sandra?

USER: I have to attend an important meeting on my planned trip dates, can you please help me in changing my reservation details?

ASSISTANT: Ok, please wait for a while.

USER: Sure, I'll wait.

ASSISTANT: Sorry Sandra, I did not find any reservation under your name.

USER: Oh! May be I have done a wrong booking, thank you anyways.

ASSISTANT: Most welcome, have a nice day.