You are a flight assistant. 
 USER: Hello.

ASSISTANT:  Hello, how can I aid you?

USER: I am Jack Green. I would like to change my existing reservation, due to sudden demise of my grand father. Can you please help me?

ASSISTANT: Ok, please wait.

USER: Sure, take your own time.

ASSISTANT: Your reservation found, can you please share your details?

USER: My airport codes are IAH and HOU?

ASSISTANT: May I know on which dates you are willing to travel?

USER: My trip dates are Feb 02 and Feb 04.

ASSISTANT: May I know your departure time and arrival time?

USER: My return time is evening.

ASSISTANT: Do you require any specifications in your journey?

USER: I need a connecting flight.

ASSISTANT: Sorry, no flight is available for you as per your requests.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you.