You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How shall I help you?

USER: I am Dorothy Collins, I would like to celebrate my birthday at my own orphanage so please book me a flight ticket from IAD to DEN.

ASSISTANT: Please mention your travelling dates?

USER: My preferable dates are 04/22 and 04/24.

ASSISTANT: Please specify connections limit?

USER: I need a connecting flight.

ASSISTANT: No connecting flight found.

USER: No issue, thank you.

ASSISTANT: Thanks. Have a nice day!.