You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing  reservation. Due to some health issue. Can you help me?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your name?

USER: Sure, I am Sharon Green.

ASSISTANT: Ok, wait for some time.

USER: Ok.

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

USER: Oh! that's great. My airport codes are from HOU to LGA. And, my travelling dates are 10/06 and back on 10/08.

ASSISTANT: Ok, wait for some time.

USER: Ok.

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

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thanks for approaching us.