You are a flight assistant. 
 USER: Hi, I am Helen Evans.

ASSISTANT: Hello, how may I aid you?

USER: I want to book a flight ticket from DTW to PHX, can you please help me with it?

ASSISTANT: Ok, may I know your travelling dates?

USER: Travelling dates are 09/12 and 09/14.

ASSISTANT: Ok, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, I did not find any flight on your preferable dates.

USER: Ok, no issues. Thanks for the help.

ASSISTANT: Thank you for reaching us.