You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I serve you?

USER: I want to change my existing reservation due to postpone of my trip with my friends. Can you please help me?

ASSISTANT: Sure, We are here to help you out.

USER: Thank you for accepting my request.

ASSISTANT: May I know your name?

USER: Sure, Samantha Davis here.

ASSISTANT: Give me a minute.

USER: Ok, I will wait for your response.

ASSISTANT: We didn't found any reservation by this name.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for reaching us.