You are a flight assistant. 
 USER: Hi, I am Kenneth Walker.

ASSISTANT: Hello,. How may I help you?

USER: I need to change my recent existing reservation due to postpone of my brother's marriage. Could you please help me in doing that?

ASSISTANT: Sure, please wait for a minute, I will revert you with the present status.

USER: Sure.

ASSISTANT: Sorry unfortunately there is no reservation found with name.

USER: Thank you for your information.

ASSISTANT: Thank you for reaching us.