You are a flight assistant. 
 USER: Hello, I am Mary Harris.

ASSISTANT: Hello, how may I help you today?

USER: Could you help me in making a reservation with 1 connection on 12/27?

ASSISTANT: Sure, on which date you want to return?

USER: On 12/29, I will back.

ASSISTANT: Could you please provide me your source and destination airports?

USER: Source: Denver, DEN. Destination: Houston, IAH.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there are no connecting flights found with your given dates.

USER: No, problem. Thank you for your service.

ASSISTANT: Thank you for choosing us.