Imports System.DirectoryServices
Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    Friend WithEvents GroupBox1 As System.Windows.Forms.GroupBox
    Friend WithEvents txtMessage As System.Windows.Forms.TextBox
    Friend WithEvents txtComputer As System.Windows.Forms.TextBox
    Friend WithEvents btnSend As System.Windows.Forms.Button
    Friend WithEvents GroupBox2 As System.Windows.Forms.GroupBox
    Friend WithEvents TreeView1 As System.Windows.Forms.TreeView
     Private Sub InitializeComponent()
        Me.GroupBox1 = New System.Windows.Forms.GroupBox
        Me.txtMessage = New System.Windows.Forms.TextBox
        Me.txtComputer = New System.Windows.Forms.TextBox
        Me.btnSend = New System.Windows.Forms.Button
        Me.GroupBox2 = New System.Windows.Forms.GroupBox
        Me.TreeView1 = New System.Windows.Forms.TreeView
        Me.GroupBox1.SuspendLayout()
        Me.GroupBox2.SuspendLayout()
        Me.SuspendLayout()
        '
        'GroupBox1
        '
        Me.GroupBox1.BackColor = System.Drawing.SystemColors.Control
        Me.GroupBox1.Controls.Add(Me.txtMessage)
        Me.GroupBox1.Controls.Add(Me.txtComputer)
        Me.GroupBox1.Controls.Add(Me.btnSend)
        Me.GroupBox1.Font = New System.Drawing.Font("Microsoft Sans Serif", 9.75!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.GroupBox1.Location = New System.Drawing.Point(152, 0)
        Me.GroupBox1.Name = "GroupBox1"
        Me.GroupBox1.Size = New System.Drawing.Size(288, 160)
        Me.GroupBox1.TabIndex = 3
        Me.GroupBox1.TabStop = False
        Me.GroupBox1.Text = "Message"
        '
        'txtMessage
        '
        Me.txtMessage.Font = New System.Drawing.Font("Microsoft Sans Serif", 9.75!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.txtMessage.ForeColor = System.Drawing.SystemColors.HotTrack
        Me.txtMessage.Location = New System.Drawing.Point(8, 24)
        Me.txtMessage.Multiline = True
        Me.txtMessage.Name = "txtMessage"
        Me.txtMessage.Size = New System.Drawing.Size(272, 88)
        Me.txtMessage.TabIndex = 1
        Me.txtMessage.Text = ""
        '
        'txtComputer
        '
        Me.txtComputer.CharacterCasing = System.Windows.Forms.CharacterCasing.Upper
        Me.txtComputer.Font = New System.Drawing.Font("Microsoft Sans Serif", 9.0!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.txtComputer.ForeColor = System.Drawing.Color.Red
        Me.txtComputer.Location = New System.Drawing.Point(8, 120)
        Me.txtComputer.Multiline = True
        Me.txtComputer.Name = "txtComputer"
        Me.txtComputer.Size = New System.Drawing.Size(144, 24)
        Me.txtComputer.TabIndex = 4
        Me.txtComputer.Text = ""
        '
        'btnSend
        '
        Me.btnSend.Font = New System.Drawing.Font("Arial", 9.75!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.btnSend.ForeColor = System.Drawing.Color.Navy
        Me.btnSend.Location = New System.Drawing.Point(192, 120)
        Me.btnSend.Name = "btnSend"
        Me.btnSend.Size = New System.Drawing.Size(88, 32)
        Me.btnSend.TabIndex = 2
        Me.btnSend.Text = "&Send"
        '
        'GroupBox2
        '
        Me.GroupBox2.Controls.Add(Me.TreeView1)
        Me.GroupBox2.Font = New System.Drawing.Font("Microsoft Sans Serif", 9.75!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.GroupBox2.Location = New System.Drawing.Point(0, 0)
        Me.GroupBox2.Name = "GroupBox2"
        Me.GroupBox2.Size = New System.Drawing.Size(144, 160)
        Me.GroupBox2.TabIndex = 5
        Me.GroupBox2.TabStop = False
        Me.GroupBox2.Text = "Select Computer"
        '
        'TreeView1
        '
        Me.TreeView1.Font = New System.Drawing.Font("Microsoft Sans Serif", 8.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.TreeView1.ForeColor = System.Drawing.Color.Red
        Me.TreeView1.ImageIndex = -1
        Me.TreeView1.Location = New System.Drawing.Point(8, 16)
        Me.TreeView1.Name = "TreeView1"
        Me.TreeView1.SelectedImageIndex = -1
        Me.TreeView1.Size = New System.Drawing.Size(128, 136)
        Me.TreeView1.TabIndex = 0
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(440, 165)
        Me.Controls.Add(Me.GroupBox2)
        Me.Controls.Add(Me.GroupBox1)
        Me.MaximizeBox = False
        Me.Name = "Form1"
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        Me.Text = "My Message"
        Me.GroupBox1.ResumeLayout(False)
        Me.GroupBox2.ResumeLayout(False)
        Me.ResumeLayout(False)

    End Sub

#End Region


    Private Sub btnSend_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSend.Click
        If txtComputer.Text <> "" And txtMessage.Text <> "" Then
            Shell("net send " & txtComputer.Text & " " & txtMessage.Text)
            txtMessage.Text = ""
            txtMessage.Focus()
        End If
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim childEntry As DirectoryEntry
        Dim ParentEntry As New DirectoryEntry
        Try
            ParentEntry.Path = "WinNT:"
            For Each childEntry In ParentEntry.Children
                Dim newNode As New TreeNode(childEntry.Name)
                Select Case childEntry.SchemaClassName
                    Case "Domain"
                        Dim ParentDomain As New TreeNode(childEntry.Name)
                        TreeView1.Nodes.AddRange(New TreeNode() {ParentDomain})

                        Dim SubChildEntry As DirectoryEntry
                        Dim SubParentEntry As New DirectoryEntry
                        SubParentEntry.Path = "WinNT://" & childEntry.Name
                        For Each SubChildEntry In SubParentEntry.Children
                            Dim newNode1 As New TreeNode(SubChildEntry.Name)
                            Select Case SubChildEntry.SchemaClassName
                                Case "Computer"
                                    ParentDomain.Nodes.Add(newNode1)
                            End Select
                        Next
                End Select
            Next
        Catch Excep As Exception
            MsgBox("Error While Reading Directories")
        Finally
            ParentEntry = Nothing
        End Try
    End Sub

    Private Sub TreeView1_AfterSelect_1(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect
        txtComputer.Text = TreeView1.SelectedNode.Text
    End Sub

End Class