You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I help you today?

USER: I am Emma White. Please, change my existing reservation as my dates of travel are postponed.

ASSISTANT: Sure, we are here to help you to change your recent reservation. Please wait for a while.

USER: Thank you.

ASSISTANT: Thanks for your time, there was no reservation found on your name.

USER: Ok, thank you for help.

ASSISTANT: Thank you for approaching us.