You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I need you to re-book my flight ticket. As I have made few changes in my plan to reach Houston. Please help me.

ASSISTANT: Sure, I am happy to help you. May I know your name?

USER: Thank you. My name is Sandra Lopez.

ASSISTANT: Thank you. Please wait, let me check your reservation status in our database.

USER: Sure, I will wait.

ASSISTANT: I am sorry to inform you that there is no reservation found under your name in our database.

USER: That's ok. Thank you.

ASSISTANT: You are welcome and thank you for choosing us.