You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Frank Lopez.

ASSISTANT: How can I help you?

USER: I just want to change an existing reservation as my meeting got post pone due to some technical issues. Can you help me?

ASSISTANT: Let me check the reservation status.

USER: Ok.

ASSISTANT: Sorry, no reservation found by your name.

USER: That's Fine. Thank you.

ASSISTANT: Thanks.