[Visual Basic]
Private Sub BlockFriendToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BlockFriendToolStripMenuItem.Click
        With tvwfriends.SelectedNode
            Try
                Dim fr As MessengerYouLike.IMSDK.Friends.MFriend

                If (.Text.ToString) = "" Then
                    Exit Sub
                End If

                fr = IMC.FindContactListFriend(.Tag.ToString)
                If fr Is Nothing Then
                    Exit Sub
                End If

                IMC.BeginFriendBlockUnBlock(fr.FriendUsername, True)

            Catch ex As Exception

            End Try
        End With
    End Sub

[Visual Basic]
Private Sub IMC_OnFriendBlocked(ByVal FriendUsername As String) Handles IMC.OnFriendBlocked
        Debug.WriteLine("Friend " & FriendUsername & " Blocked")
    End Sub

[Visual Basic]
Private Sub IMC_OnFriendAMIBlocked(ByVal FriendUsername As String) Handles IMC.OnFriendAMIBlocked
        Debug.WriteLine("You have been blocked by :" & FriendUsername)
End Sub