You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Ryan Collins.

ASSISTANT: How may I help you?

USER: Due to some issues I have to change my flight ticket booking, can you please help me in flight ticket modification?

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found basis on your details.

USER: Not an issue with that one, thank you for your search and providing the information.

ASSISTANT: Most welcome.