You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Sandra Gonzalez. I want to change my travel dates in my previous reservation, due to some problems I am unable to travel those dates so can you please help me with that?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: There is no reservation found under your name.

USER: Oh! It's ok no problem. Thank you for your information.

ASSISTANT: Most welcome.