You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change my existing reservation which is done recently due to some problems, can you please help me in this?

ASSISTANT: Sure, may I know your name for the changing process?

USER: Sure my name is Benjamin Williams.

ASSISTANT: Your change reservation found. Can you provide your new planned travel dates?

USER: Ok, my dates of journey are from Mar, 31 to Apr, 02.

ASSISTANT: May I know your airport codes please?

USER: Sure, my respective airport codes are from CLT to IAD>.

ASSISTANT: Do you have any limits on number of connections?

USER: Yes, I need a connecting flight.

ASSISTANT: Do you have any another specifications?

USER: No.

ASSISTANT: Sorry, no flights are available on your route.

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

ASSISTANT: Welcome, thank you for reaching us.