You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I serve you?

USER: I need to reschedule my journey dates as per my trip, can you help me in change an existing reservation?

ASSISTANT: Sure. let me know your good name please.

USER: I am Sharon Anderson.

ASSISTANT: Ok, please wait a minute.

USER: Ok.

ASSISTANT: Unfortunately there is no reservation found according to your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for availing us.