Powershell: Select CSV Colums to create new CSV

My first small project with Forms. Run the script with .\modifycsv.ps1 -file .\csvfile.csv

[CmdletBinding()]
Param(
  [Parameter(Mandatory=$True,Position=1)]
    [string]$file,
  [parameter()]
    [string]$delimiter = ";"
)
 
$csv = import-csv $file -Delimiter $delimiter
$headers = $csv | get-member -membertype NoteProperty | select-object -ExpandProperty 'Name'
$x = @()
 
 
$headers = $csv | get-member -membertype NoteProperty | select-object -ExpandProperty 'Name'
$x = @()



<# FORM START ---------------------------------------------------------------------#>
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Drawing") 

$objForm = New-Object System.Windows.Forms.Form 
$objForm.Text = "Data Entry Form"
$objForm.Size = New-Object System.Drawing.Size(300,200) 
$objForm.StartPosition = "CenterScreen"

$objForm.KeyPreview = $True

$objForm.Add_KeyDown({if ($_.KeyCode -eq "Enter") 
    {
        foreach ($objItem in $objListbox.SelectedItems)
            {$x += $objItem}
        $objForm.Close()
    }
    })

$objForm.Add_KeyDown({if ($_.KeyCode -eq "Escape") 
    {$objForm.Close()}})

$OKButton = New-Object System.Windows.Forms.Button
$OKButton.Location = New-Object System.Drawing.Size(75,120)
$OKButton.Size = New-Object System.Drawing.Size(75,23)
$OKButton.Text = "OK"

$OKButton.Add_Click(
   {
        foreach ($objItem in $objListbox.SelectedItems)
            {$x += $objItem}
        $objForm.Close()
   })

$objForm.Controls.Add($OKButton)

$CancelButton = New-Object System.Windows.Forms.Button
$CancelButton.Location = New-Object System.Drawing.Size(150,120)
$CancelButton.Size = New-Object System.Drawing.Size(75,23)
$CancelButton.Text = "Cancel"
$CancelButton.Add_Click({$objForm.Close()})
$objForm.Controls.Add($CancelButton)

$objLabel = New-Object System.Windows.Forms.Label
$objLabel.Location = New-Object System.Drawing.Size(10,20) 
$objLabel.Size = New-Object System.Drawing.Size(280,20) 
$objLabel.Text = "Please make a selection from the list below:"
$objForm.Controls.Add($objLabel) 

$objListbox = New-Object System.Windows.Forms.Listbox 
$objListbox.Location = New-Object System.Drawing.Size(10,40) 
$objListbox.Size = New-Object System.Drawing.Size(260,20) 

$objListbox.SelectionMode = "MultiExtended"

<# DATA INPUT -------------------------------------------------------------#>
write-output $headers | ForEach-Object {[void] $objListBox.Items.Add($_)}


$objListbox.Height = 70
$objForm.Controls.Add($objListbox) 
$objForm.Topmost = $True

$objForm.Add_Shown({$objForm.Activate()})
[void] $objForm.ShowDialog()
<# FORM END --------------------------------------------------------------#>



Write-Output $csv | select-object -property $objlistbox.selecteditems | export-csv .\CSVOutput.csv -NoTypeInformation