static extern bool IcmpCloseHandle(IntPtr handle);

Declare Function IcmpCloseHandle Lib "icmp.dll" (IntPtr handle) As Boolean

        private static extern bool IcmpCloseHandle(IntPtr handle);

            IcmpCloseHandle(icmpHandle);

WINBOOL WINAPI IcmpCloseHandle(HANDLE IcmpHandle);

    IcmpCloseHandle(hIcmpFile);