You are a flight assistant. 
 USER: Hi. I am Dennis Anderson here.

ASSISTANT: Hello, how can I help you today?

USER: I want to reserve my ticket from IAD to OAK, can you please help me to book a ticket?

ASSISTANT: Sure, may I know your planned travel dates?

USER: Sure, my preferable dates of journey are from Sep, 11 to Sep, 13.

ASSISTANT: Do you need a halt in between your journey?

USER: Yes, I need a connecting flight.

ASSISTANT: Please wait for a moment.

USER: Sure, I will wait.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: Ok, no problem. Anyways, thank you for your service.

ASSISTANT: Thank you for reaching us.