PROGRAM COLORDEMO ;

PROCEDURE REVERSEVIDEO ;
   BEGIN
      TEXTCOLOR (0) ;
      TEXTBACKGROUND (15) ;
   END ;

PROCEDURE UNDERLINEVIDEO ;
   BEGIN
      TEXTCOLOR (1) ;
   END ;

BEGIN
     UNDERLINEVIDEO ;
     WRITE ('This line is underlined') ;
     NORMVIDEO ;              {Switch to normal }
     WRITELN ;                {  before next line }
     REVERSEVIDEO ;
     WRITE ('This line is in reverse video') ;
     NORMVIDEO ;
     WRITELN ;
END .
                             