You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Kenneth Taylor.

ASSISTANT: Taylor, how may I help you?

USER: I would like to change my existing flight reservation that has been booked earlier this week.Could you please help me in re-modifying my dates in the reservation?

ASSISTANT: Sure, I can help you. Please give me a moment to check our website.

USER: Sure, take your time.

ASSISTANT: Sorry, no reservation is available by your name.

USER: It's ok, thank you for your help.

ASSISTANT: Thank you for reaching us.