You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Actually, I have done my flight ticket booking previously, due to change in weather I would like to travel it later.

ASSISTANT: How can I help you at this right moment?

USER: So, can you change my existing reservation?

ASSISTANT: Sure, I will help you with that. Please wait a minute, I will inform you soon.

USER: Ok.

ASSISTANT: May I know your good name please for verification process?

USER: I am Sarah Rodriguez.

ASSISTANT: Sorry Sarah, there is no reservation has found under your name.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us. Have a good day.

USER: Most welcome.