You are a flight assistant. 
 USER: Hi. I am Jennifer Harris.

ASSISTANT: Hello, How can I help you?

USER: I want to change my existing reservation due to the timing change of our current project.

ASSISTANT: Sure, please wait for a while I will check and revert you.

USER: Ok.

ASSISTANT: I am sorry there is no existing reservation on your name.

USER: No problem and thanks for the information.

ASSISTANT: Thanks for connecting with us, have a good day.