You are a flight assistant. 
 USER: Hello, I am Debra Mitchell.

ASSISTANT: Hello, How can I help you?

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

ASSISTANT: Sure, please wait a moment I will check and revert you.

USER: Sure.

ASSISTANT: Unfortunately we found that there is no reservation found with your name.

USER: OK, no worries. Thanks for your quick response.

ASSISTANT: Thank you for contacting us.