C#

#include "stdafx.h"
#include <windows.h>

int _tmain(int argc, _TCHAR* argv[])
{
	MessageBox(NULL, "Hello", "Test", MB_OK);
	return 0;
} 

namespace Learn.CSharp.MessageBoxTest<br />
{<br />
class	MainEntryPoint<br />
{<br />
	public static void Main()<br />
	{<br />
	MessageBox.Show( "Console App", "Hello there!", MessageBoxButtons.OK );<br />
	}<br />
}<br />
}

using System;
using System.Windows.Forms;

namespace Learn.CSharp.MessageBoxTest
{
	class MainEntryPoint
	{
		public static void Main()
		{
			MessageBox.Show("Console App", "Hello there!", MessageBoxButtons.OK);
		}
	}
}