You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I support you today?

USER: I am Christopher Mitchell. I want to book a flight ticket from DC-IAD to TX-IAH. Can you help me?

ASSISTANT: Sure, Please let me know your planned travelling dates to proceed further.

USER: 04/23 and 04/25 are my travelling dates.

ASSISTANT: Do you have any other specifications?

USER: I need a connecting flight.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, unfortunately there are no flights found with your essential details.

USER: No issue.

ASSISTANT: Thank you for availing us.

USER: Thank you.