You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Due to some technical issues, my meeting place has been changed. Can you please change my existing reservation?

ASSISTANT: Sure, may I know your name please?

USER: Sure, I am Dennis Johnson.

ASSISTANT: Please be on hold.

USER: Sure, I will wait for your response.

ASSISTANT: Thank you for your time. Sorry, there is no reservation matching with your name in our portal to make changes further.

USER: Ok, Thank you for providing information.

ASSISTANT: Thank you for reaching us. Hope to serve you again.