PowerShell GUIs: Active Directory TreeView

So this is a modified bit of code I wrote to build a tree-view of the local Active Directory OU structure. I'm using this snippet in another piece of code but it *should* work just fine in any domain. Please let me know of any modifications or fixes necessary.

function Add-Node { 
        param ( 
            $selectedNode, 
            $name
        ) 
        $newNode = new-object System.Windows.Forms.TreeNode  
        $newNode.Name = $name 
        $newNode.Text = $name 
        $selectedNode.Nodes.Add($newNode) | Out-Null 
        return $newNode 
} 

function Get-NextLevel {
    param (
        $selectedNode,
        $dn
   )
   
    $OUs = Get-ADObject -Filter 'ObjectClass -eq "organizationalUnit" -or ObjectClass -eq "container"' -SearchScope OneLevel -SearchBase $dn

    If ($OUs -eq $null) {
        $node = Add-Node $selectedNode $dn
    } Else {
        $node = Add-Node $selectedNode $dn
        
        $OUs | % {
            Get-NextLevel $node $_.distinguishedName
        }
    }
}
 
function Build-TreeView { 
    if ($treeNodes)  
    {  
          $treeview1.Nodes.remove($treeNodes) 
        $form1.Refresh() 
    } 
    
    $treeNodes = New-Object System.Windows.Forms.TreeNode 
    $treeNodes.text = "Active Directory Hierarchy" 
    $treeNodes.Name = "Active Directory Hierarchy" 
    $treeNodes.Tag = "root" 
    $treeView1.Nodes.Add($treeNodes) | Out-Null 
     
    $treeView1.add_AfterSelect({ 
        $textbox1.Text = $this.SelectedNode.Name
    }) 
     
    #Generate Module nodes 
    $OUs = Get-NextLevel $treeNodes $strDomainDN
    
    $treeNodes.Expand() 
} 
 
#Generated Form Function 
function GenerateForm { 
 
    #region Import the Assemblies 
    Import-Module ActiveDirectory
    [reflection.assembly]::loadwithpartialname("System.Windows.Forms") | Out-Null 
    [reflection.assembly]::loadwithpartialname("System.Drawing") | Out-Null 
    $objIPProperties = [System.Net.NetworkInformation.IPGlobalProperties]::GetIPGlobalProperties()
    $strDNSDomain = $objIPProperties.DomainName.toLower()
    $strDomainDN = $strDNSDomain.toString().split('.'); foreach ($strVal in $strDomainDN) {$strTemp += "dc=$strVal,"}; $strDomainDN = $strTemp.TrimEnd(",").toLower()
    #endregion 
     
    #region Generated Form Objects 
    $form1 = New-Object System.Windows.Forms.Form 
    $treeView1 = New-Object System.Windows.Forms.TreeView 
    $label1 = New-Object System.Windows.Forms.Label
    $textbox1 = New-Object System.Windows.Forms.TextBox
    $InitialFormWindowState = New-Object System.Windows.Forms.FormWindowState 
    #endregion Generated Form Objects 
     
    #---------------------------------------------- 
    #Generated Event Script Blocks 
    #---------------------------------------------- 
    $button1_OnClick=  
    { 
    $form1.Close() 
     
    } 
     
    $OnLoadForm_StateCorrection= 
    {Build-TreeView 
    } 
     
    #---------------------------------------------- 
    #region Generated Form Code 
    $form1.Text = "Form" 
    $form1.Name = "form1" 
    $form1.DataBindings.DefaultDataSourceUpdateMode = 0 
    $form1.ClientSize = New-Object System.Drawing.Size(400,500) 
     
    $treeView1.Size = New-Object System.Drawing.Size(350,375)
    $treeView1.Name = "treeView1" 
    $treeView1.Location = New-Object System.Drawing.Size(15,15)
    $treeView1.DataBindings.DefaultDataSourceUpdateMode = 0 
    $treeView1.TabIndex = 0 
    $form1.Controls.Add($treeView1)
    
    $label1.Name = "label1" 
    $label1.Location = New-Object System.Drawing.Size(15,400)
    $label1.Size = New-Object System.Drawing.Size(350,20)
    $label1.Text = "Selected Value:"
    $form1.Controls.Add($label1) 
    
    $textbox1.Name = "textbox1" 
    $textbox1.Location = New-Object System.Drawing.Size(15,425)
    $textbox1.Size = New-Object System.Drawing.Size(350,20)
    $textbox1.Text = ""
    $form1.Controls.Add($textbox1) 
     
     
    #endregion Generated Form Code 
     
    #Save the initial state of the form 
    $InitialFormWindowState = $form1.WindowState 
    #Init the OnLoad event to correct the initial state of the form 
    $form1.add_Load($OnLoadForm_StateCorrection) 
    #Show the Form 
    $form1.ShowDialog()| Out-Null 
     
} #End Function 
 
#Call the Function 
GenerateForm