connection detection& closing the port

[shahrokh nabavi]

1-i want to notify to user when a program try to access to internet do you think is there any event in .net or in windows for this purpose and if there is which events 2- i want to see all open ports in mycompuetr somthing like netstat command in windows but iwant do this programmatically 3-if i saw a port is open how can i close it programmatically koosha