You are a flight assistant. 
 USER: Hello. I am Sarah Gonzalez.

ASSISTANT: Hello, how can I help you today?

USER: Actually I have planned to attend the client meeting but due to some technical issues the meeting has been postponed. Could you please help me to change my reservation?

ASSISTANT: Sure, please wait for a while.

USER: Ok, I will wait for your response.

ASSISTANT: Sorry, there was no reservation found with your given name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.