you made it so the dialog box instantly closes and the powershell window still can be closed by clicking top right

To set up a PowerShell script that opens a dialog box and immediately closes it while allowing the PowerShell window to remain open (and also closeable via the top right corner), you can make use of Windows Forms in PowerShell.

Here's a basic example of how to implement that in a PowerShell script:

```powershell
# Load the necessary assembly to use Windows Forms
Add-Type -AssemblyName System.Windows.Forms

# Create a function to show the dialog box
function Show-Dialog {
    # Create a new message box
    [System.Windows.Forms.MessageBox]::Show("This is a dialog box", "Dialog Title", [System.Windows.Forms.MessageBoxButtons]::OK)

    # Optionally you can add a sleep period before closing, but if you want an immediate closure,
    # simply call this method without any delay.
}

# Call the Show-Dialog function
Show-Dialog

# Just keep the PowerShell window open until the user closes it
Write-Host "Press any key to exit the PowerShell window..."
[void][System.Console]::ReadKey()
```

### Explanation:
1. **Add-Type**: This line imports the `System.Windows.Forms` assembly to enable the creation of GUI components, such as dialog boxes.
2. **Show-Dialog Function**: This function creates a message box that will pop up with an OK button. It can be configured to display any message.
3. **ReadKey**: This makes the script wait for the user to press a key before the PowerShell window closes, allowing the user to click the close button on the PowerShell window too.

### Installation:
1. Open PowerShell ISE or any text editor, and paste the script above.
2. Save it as `DialogBoxExample.ps1`.
3. Run the script in PowerShell.

### Note:
- The dialog box will appear and will not automatically close until you click the OK button. If you require the dialog box to appear and then close on its own after a certain time, you can implement a timer or a delay. However, the user can always close the PowerShell window using the top-right corner.