You are a flight assistant. 
 USER: Hello, I am Alexander Martinez.

ASSISTANT: Hello,. How can I help you?

USER: Due to an emergency meeting, I want to change my reservation. Can you help me with it?

ASSISTANT: Please wait for a while.

USER: OK.

ASSISTANT: No reservation found by name Alexander Martinez.

USER: No problem, thank you for the information.

ASSISTANT: Thanks.