You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I help you today?

USER: I need to change my existing reservation as my travelling dates to meet family are postponed.

ASSISTANT: Sure, please wait for a while.

USER: I am Samantha King. Sure.

ASSISTANT: Thanks for your patience, we found a new reservation on your given name. Can you please provide your new journey details?

USER: Sure. Atlanta , ATL - Dallas DFW are my airport codes. I need a direct flight. The dates of travel are 10/27 - 10/29.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Unfortunately, no flight found on your given journey details.

USER: Ok, no problem.

ASSISTANT: Thanks for choosing us.

USER: Thank you for assisting me.