You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: My name is David Martinez. Can you help me to change the reservation I had done recently?

ASSISTANT: Sure, I will help you with that.

USER: Ok, thank you.

ASSISTANT: Please wait for a moment, while I search for your reservation.

USER: Please take your own time.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system data.

USER: That is ok, thank you for the information.

ASSISTANT: Thank you for reaching us, we hope see you again.