using System;
using System.Runtime.InteropServices;
 
public class Test
{
	DllImport("user32.dll")]
    public static extern int MessageBoxA(int h, string text, string caption, int options); 
 
    public static 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);
    }
}