You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Anthony Taylor.

ASSISTANT: How may I help you?

USER: I would like to change my existing reservation. As my plans to visit Dallas got postponed, will you help me with this?

ASSISTANT: Please wait for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there is no reservation matching with your name in our portal.

USER: Ok, not an issue. Thank you for providing information.

ASSISTANT: Most welcome.