You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I am Alexander Martin. Owing an emergency want to change my reservation, can you help me with it please?

ASSISTANT: Sure, I am happy to help you. Please wait, let me check your reservation status in our database.

USER:   Ok.

ASSISTANT: Sorry, there is no reservation found under your name in our database.

USER:    That's ok, thank you for the response.

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