function Load-Form {
    $Form.Controls.Add($TBComputerName)
    $Form.Controls.Add($GBComputerName)
    $Form.Controls.Add($ButtonOK)
    $Form.Controls.Add($Label)
    $Form.Add_Shown({$Form.Activate()})
    [void] $Form.ShowDialog()
}

 function Set-OSDComputerName {
     $ErrorProvider.Clear()
     if ($TBComputerName.Text.Length -eq 0) {
         $ErrorProvider.SetError($GBComputerName, "Please enter a computer name")
     }
     else {
         if ($TBComputerName.Text.Length -gt 7) {
             $ErrorProvider.SetError($GBComputerName, "Computer name cannot be more than 6 characters")
         }
             else {
         if ($TBComputerName.Text -notmatch '^[F][0-9]{2,2}[a-zA-Z]{4,4}$') {
             $ErrorProvider.SetError($GBComputerName, "Computer name must be named with <F> and <numbers> and <four random letters>")
         }
       
         else {                       
             $OSDComputerName = $TBComputerName.Text -replace "[\[\]:;|=+*?<>\/,]+", ''
             $TSEnv = New-Object -COMObject Microsoft.SMS.TSEnvironment 
             $TSEnv.Value("OSDComputerName") = "$($OSDComputerName)"
             $Form.Close()
           }
        }
     }
 }



[void][System.Reflection.Assembly]::LoadWithPartialName("System.Drawing") 
[void][System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms") 

$Global:ErrorProvider = New-Object System.Windows.Forms.ErrorProvider


$Form = New-Object System.Windows.Forms.Form    
$Form.Size = New-Object System.Drawing.Size(300,300)  

$Form.StartPosition = "CenterScreen"
$Form.SizeGripStyle = "Hide"
$Form.Text = "Enter Computer Name"
$Form.ControlBox = $false
$Form.TopMost = $true

$TBComputerName = New-Object System.Windows.Forms.TextBox
$TBComputerName.Location = New-Object System.Drawing.Size(25,30) 
$TBComputerName.Size = New-Object System.Drawing.Size(215,50)
$TBComputerName.TabIndex = "1"

$GBComputerName = New-Object System.Windows.Forms.GroupBox
$GBComputerName.Location = New-Object System.Drawing.Size(20,10) 
$GBComputerName.Size = New-Object System.Drawing.Size(225,50) 
$GBComputerName.Font = [System.Drawing.Font]::new("Corbel", 9, [System.Drawing.FontStyle]::Regular)
$GBComputerName.Text = "Computer name:" 

$ButtonOK = New-Object System.Windows.Forms.Button 
$ButtonOK.Location = New-Object System.Drawing.Size(195,70) 
$ButtonOK.Size = New-Object System.Drawing.Size(50,20) 
$ButtonOK.Text = "OK"
$ButtonOK.TabIndex = "2"
$ButtonOK.Add_Click({Set-OSDComputerName})

$Label = New-Object System.Windows.Forms.Label
$Label.Location = New-Object System.Drawing.Size(20,100)
$Label.Size = New-Object System.Drawing.Size((225,150) )
$Label.Font = [System.Drawing.Font]::new("Corbel", 10, [System.Drawing.FontStyle]::Regular)
$Label.Text = "Just some information to end users"


Load-Form