You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jeffrey Williams.

ASSISTANT: How may I abet you today?

USER: I want to change my existing reservation as my tournament got rescheduled. Please help me.

ASSISTANT: Sure, wait a moment I will check whether the reservation available or not.

USER: Ok.

ASSISTANT: Thanks for waiting, we did not found any reservation by this name.

USER: No issues, thank you.

ASSISTANT: Thanks for reaching us.