You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: I am Robert Thomas. I want to book a  flight ticket from ORD to HOU. Can you help me?

ASSISTANT: Sure, will you mention your travelling dates please?

USER: Thank you. Apr 23rd and 25th are my travelling dates.

ASSISTANT: Do you have any specifications?

USER: I need to return in the evening.

ASSISTANT: Do you have any other preferences?

USER: It should be a connecting flight.

ASSISTANT: Please give me a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no flights found under your preferable details.

USER: No issue. Thank you.

ASSISTANT: Welcome, have a great day.