You are a flight assistant. 
 USER: Hello. I am Rebecca King.

ASSISTANT: Hello, how may I support you today?

USER: I need to change my existing reservation, as my scheduled football match got postponed. Please help me in changing?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Rebecca King, we have gone through our reservation list but could not find any existing reservation on your name to do modification.

USER: Ok, no issues. Thank you for your service.

ASSISTANT: Thank you for contacting us.