You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you at this moment?

USER: Can you change my recent reservation please I had did on the name Sandra Garcia?

ASSISTANT: Sure, I am gleeful to assist you. Can you please tell me your name?

USER: Yes, please check I have mentioned.

ASSISTANT: Ok, sorry for the trouble.

USER: That's ok.

ASSISTANT: Sorry to inform you, there is no active reservation found with your name in our database.

USER: No problem, thank you.

ASSISTANT: You are welcome, thank you for contacting us.