MessageBox
MessageBox(var Message,var Title,var Icon,var Buttons)
  This function displays a message box, and returns 1 if the OK or YES button is pressed and 0 if the CANCEL or NO button is pressed. This function takes four arguments. The first one is the message itself. The second one is the title of the message box. The third one is which icon you want to use. The last one specifies what button set you want to use. There are four different icon types and three different button combinations.
 
  Icon:
    0 = Information
    1 = Warning
    2 = Error
    3 = Question
 
  Buttons:
    0 = OK
    1 = YES and NO
    2 = OK and CANCEL
 
  Example:
 

function main()
{
     MessageBox("Hello World!","",0,0);
}