You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. I hope you are good today, how can I assist you?

USER: I am Jessica Hernandez from Philadelphia. I want to change my travel dates in my previous reservation, can you help me with that?

ASSISTANT: Sure Jessica, I will check the previous reservation.

USER: Thank you.

ASSISTANT: Did you reserved the ticket on the name Jessica Hernandez?

USER: Yes, I reserved my previous ticket in my name.

ASSISTANT: Ok, wait a while.

USER: Sure.

ASSISTANT: I am sorry to say, there is no previous reservation on your name.

USER: Oh! It's ok no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us, have a nice day, if you have any query's contact us.