/* - acessibilidade.js - */
function contrastOn ()
{
  var p = document.getElementsByTagName ('*');
  for (var i = 0; i < p.length; i++)
    {
      var style = p[i].style;
      var foreground = style.color;
      var background = style.backgroundColor;

      if (!foreground)
        foreground = '#000';

      if (!background)
        background = '#fff';

      var aux = foreground;
      foreground = background;
      background = aux;

      style.backgroundColor = background;
      style.color = foreground;
    }
}

function contrastOff ()
{
  var p = document.getElementsByTagName ('*');
  for (var i = 0; i < p.length; i++)
    {
      var style = p[i].style;
      var foreground = style.color;
      var background = style.backgroundColor;

      foreground = '';
      background = '';

      var aux = foreground;
      foreground = background;
      background = aux;

      style.backgroundColor = background;
      style.color = foreground;
    }
}