You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: My name is Amy Robinson. I want to change me existing reservation due to my plan to meet my friend got postponed, can you please help me in doing that?

ASSISTANT: Sure, please wait for a minute.

USER: Sure.

ASSISTANT: Sorry for the trouble which is caused to you, there is no reservation found with your name in our system data to change the travelling dates.

USER: No problem, may be I did with my other agent. Thank you for the information.

ASSISTANT: Thanks for choosing us, have a great day ahead.