You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I need to change my reservation due to my planned event got postponed so please help me with that.

ASSISTANT: Sure, I will help you with this.

USER: Thank you.

ASSISTANT: Can you please provide the name on which you have done the reservation previously?

USER: Sure, please check with my name Carolyn Mitchell.

ASSISTANT: Carolyn Mitchell, there is no active reservation found under your name in our database.

USER: Oh! May be booking has not done properly.

ASSISTANT: Thank you for contacting us.

USER: Anyway, thank you for your help.