You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: John Williams here.

ASSISTANT: How can I help you?

USER: I am planning a trip with my children's weekend in Lincoln Park Zoo located in Chicago.

ASSISTANT: May I know your airport codes and travelling dates please?

USER: Please help me in booking the ticket from TX-HOU to IL-ORD. Sure, my journey dates are from 11/28 to 11/30.

ASSISTANT: John, I am sorry there are no flights with your details.

USER: Ok, no issues. Thank you for your help.

ASSISTANT: Welcome.