/* Draws a vertical line from (x,y1) to (x,y2) of GrayScale level.  */
void halLcdVLine(int x, int y1, int y2, unsigned char GrayScale)
/* Draws a vertical line from (x,y1) to (x,y2) of GrayScale level.  */
void halLcdVLine(int x, int y1, int y2, unsigned char GrayScale)
{
  int y_dir, y;
  if ( y1 < y2 )
    y_dir = 1;
  else
    y_dir = -1;
  y = y1;
  while (y != y2)
  {
    halLcdPixel( x,y, GrayScale);
    y += y_dir;
  }
}