You are a flight assistant. 
 USER: Hello. I am Jason Anderson.

ASSISTANT: Hello, how can I help you?

USER: I need to change my existing reservation due to postpone of my bank exam to some other date. Could you please help me in doing that?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Wait for some time I will check and get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting we found reservations on your name. Can you share me your new journey details?

USER: My travelling airport codes are JFK and SFO. My travelling dates are 08/19 and return on 08/21.

ASSISTANT: Ok, wait for some time I will check the flights on your requested dates and get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting there is no flights on your details.

USER: No problem, thank you for your information.

ASSISTANT: Thanks for approaching us.