using System;
using System.Runtime.InteropServices;
 
public class Test
{
	public static extern int MessageBoxA(
		[MarshalAs(UnmanagedType.I4)] int h, 
		[MarshalAs(UnmanagedType.LPStr)] string text, 
		[MarshalAs(UnmanagedType.LPStr)]  string caption, 
		[MarshalAs(UnmanagedType.I4)]  int options
	);
	public static void Main()
	{
	    MessageBoxA(0, "Hello!", "Message", 0);
	    MessageBoxA(0, "OK or cancel?", "Dialog", 1);
	    MessageBoxA(0, "Abort, retry or skip?", "Fail", 2);
	    MessageBoxA(0, "Yes, no or cancel?", "What to do?", 3);
	    MessageBoxA(0, "Yes or no?", "Dialog?", 4);
	}
}