You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me to change the travel dates in the past reservation?

ASSISTANT:  To proceed further, can I have your name please?

USER: My name is Jennifer Johnson.

ASSISTANT: Thank you. Please be online for a while. I will check your reservation status and get back to you.

USER: Ok, take your time.

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

USER: It's ok, not a problem with that. Thank you for your time.

ASSISTANT: Welcome Jennifer Johnson.