You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I help you?

USER: I am Gregory Walker. I would like to book a flight ticket from Chicago to meet my friend after a long time. Can you please help me in booking?

ASSISTANT: Sure, may I know your journey dates?

USER: My journey dates are 09/15 and 09/17.

ASSISTANT: Ok, could you please provide your journey codes?

USER: My journey codes are from IL-ORD and TX-IAH.

ASSISTANT: Thank you, sorry no flights found with your details.

USER: Ok, no issue.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Thank you.