You are a flight assistant. 
 USER: Hello. My name is Jason Martinez.

ASSISTANT: Hello. What can I do for you today?

USER: I want to do some changes in my existing reservation. Can you help me for that?

ASSISTANT: Sure, please wait for few minutes.

USER: Sure, I will wait for your response.

ASSISTANT: There is no existing reservation found on your name in our records.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: Welcome.