MessageBox(HWND hWndParent, BYTE *pszString, BYTE *pszCaption, WORD wFlags)

Parameters
  hWndParent can be NULLHWND or the handle to a window which is the message
                box's parent. If you give NULLHWND as this argument,
                you will always be safe.

  pszString is the textual information which will be displayed inside of
                the message box. It can have embedded carriage returns in
                it when you want a new line to begin. The MessageBox()
                logic will determine the number of lines that the message
                box will be, the centering of the strings, and will take
                care of wordwrapping. Embedded newlines are not necessary
                unless you want to have control over where new lines begin.

  The rest of the arguments are the same as in previous versions.


TIP
        The quickest way to get existing code to work with the new version
        of MessageBox, is to define a new function : OldMessageBox , that
        takes the old message box syntax and translates it to the new.
        Then a simple 'Global Find & Change' on MessageBox to OldMessageBox
        will get you going. The definition of OldMessageBox below will
        produce message boxes that, in most instances, look just like
        pre-V3.1 message boxes.  The exception to this is for message boxes
        that had very long lines, these will probably end up being massaged
        by the new MessageBox and end up with more lines.

int PASCAL OldMessageBox(BYTE *text1,BYTE *text2,BYTE *text3,
                                 BYTE *caption,unsigned short wType)
{
   char * pMessageBuffer;
   int iResult;

   pMessageBuffer = emalloc(strlen(text1)+strlen(text2)+strlen(text3)+3);
   *pMessageBuffer = '\0';
   if (text1)
      strcat(pMessageBuffer, text1);
   strcat(pMessageBuffer, "\n");

   if(text2)
      strcat(pMessageBuffer, text2);
   strcat(pMessageBuffer, "\n");

   if(text3)
      strcat(pMessageBuffer, text3);

   iResult = MessageBox(NULLHWND, pMessageBuffer, caption,  wType);
   MyFree(pMessageBuffer);
   return(iResult);
}