Get focus on .NET pop-up window

Hello All

I have written a nice little PS script that creates a series pop-up boxes (.NET) that prompts the user for keyed in information. I am using this method:

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

The problem that I am encountering is when I run my script, it never allows me to type without clicking the box at each new input prompt. A snippet of my script looks like this:

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

##Display primary screen##

do{

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

$objForm.KeyPreview = $True
$objForm.Add_KeyDown({if ($_.KeyCode -eq "Enter")
    {$Main=$objTextBox.Text;$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(110,210)
$OKButton.Size = New-Object System.Drawing.Size(75,23)
$OKButton.Text = "OK"
$OKButton.Add_Click({$Main=$objTextBox.Text;$objForm.Close()})
$objForm.Controls.Add($OKButton)

$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 select options:"
$objForm.Controls.Add($objLabel)

$objLabel = New-Object System.Windows.Forms.Label
$objLabel.Location = New-Object System.Drawing.Size(10,100)
$objLabel.Size = New-Object System.Drawing.Size(280,100)
$objLabel.Text = $MainText
$objForm.Controls.Add($objLabel)

$objTextBox = New-Object System.Windows.Forms.TextBox
$objTextBox.Location = New-Object System.Drawing.Size(10,40)
$objTextBox.Size = New-Object System.Drawing.Size(260,20)
$objForm.Controls.Add($objTextBox)

$objForm.Topmost = $True

$objForm.Add_Shown({$objForm.Activate()})
[void] $objForm.ShowDialog()

$Main

My question is, how can I display this box so that I can just type without having to click in the box? is it a focus issue or something else?

Thank you in advance!

Greg