write windows network filter!

["swin" <swin () student dlut edu cn>]

hi!
        I currently want to write a simple network fiter on
windows platform, but I'm not sure how to intercept
package on windows and how to stop it,do anyone
have this experience,and any link about this.
        thanks in advance.

　　　　　　　　swin
　　　　　　　　swin () student dlut edu cn
　　　　　　　　　　2003-01-11