FlashWindow

C# Signature:

[DllImport("user32.dll")]
static extern bool FlashWindow(IntPtr hwnd, bool bInvert);

VB.NET Signature:

<DllImport("user32.dll")> _
Private Shared Function FlashWindow(hwnd As IntPtr, bInvert As Boolean) As Boolean
End Function

Sample Code:

[DllImport("user32.dll")]
    private static extern bool FlashWindow(IntPtr hwnd, bool bInvert);

    public static void FlashWindow(System.Windows.Forms.Form window)
    {
        FlashWindow(window.Handle, false);
    }