/**

 * Darkens the browser screen. This will make the entire page un-clickable except for any floating divs created after this is called. Restore with enlighten().

 * @param bool Controls whether the fade should be disabled or not. aclDisableTransitionFX will override this if set to true, and fades are never fired on IE.

 * @param int When specified, represents the numeric opacity value to set the fade layer to. 1-100.

 */

var darkener_index = 0;

function darken(nofade, opacVal)

{

  if(IE)

    nofade = true;

  if ( !opacVal )

    opacVal = 70;

  darkener_index++;

  if(document.getElementById('specialLayer_darkener'))

  {

    if(nofade)

    {

      changeOpac(opacVal, 'specialLayer_darkener');

      document.getElementById('specialLayer_darkener').style.display = 'block';

      document.getElementById('specialLayer_darkener').myOpacVal = opacVal;

    }

    else

    {

      if ( document.getElementById('specialLayer_darkener').style.display != 'none' )

      {

        var currentOpac = document.getElementById('specialLayer_darkener').myOpacVal;

        opacity('specialLayer_darkener', currentOpac, opacVal, 1000);

        document.getElementById('specialLayer_darkener').myOpacVal = opacVal;

      }

      else

      {

        document.getElementById('specialLayer_darkener').style.display = 'block';

        document.getElementById('specialLayer_darkener').myOpacVal = opacVal;

        opacity('specialLayer_darkener', 0, opacVal, 1000);

      }

    }

  } else {

    w = getWidth();

    h = getHeight();

    var thediv = document.createElement('div');

    if(IE)

      thediv.style.position = 'absolute';

    else

      thediv.style.position = 'fixed';

    if ( IE )

    {

      var top = getScrollOffset();

      thediv.style.top = String(top) + 'px';

    }

    else

    {

      thediv.style.top = '0px';

    }

    thediv.style.left = '0px';

    thediv.style.opacity = '0';

    thediv.style.filter = 'alpha(opacity=0)';

    thediv.style.backgroundColor = '#000000';

    thediv.style.width =  '100%';

    thediv.style.height = '100%';

    thediv.zIndex = getHighestZ() + 5;

    thediv.id = 'specialLayer_darkener';

    thediv.myOpacVal = opacVal;

    if(nofade)

    {

      thediv.style.opacity = ( parseFloat(opacVal) / 100 );

      thediv.style.filter = 'alpha(opacity=' + opacVal + ')';

      body = document.getElementsByTagName('body');

      body = body[0];

      body.appendChild(thediv);

    } else {

      body = document.getElementsByTagName('body');

      body = body[0];

      body.appendChild(thediv);

      opacity('specialLayer_darkener', 0, opacVal, 1000);

    }

  }

}

/**

 * Un-darkens the screen and re-enables clicking of on-screen controls.

 * @param bool If true, disables the fade effect. Fades are always disabled if aclDisableTransitionFX is true and on IE.

 */

function enlighten(nofade)

{

  if(IE)

    nofade = true;

  darkener_index -= 1;

  if ( darkener_index > 0 )

    return false;

  if(document.getElementById('specialLayer_darkener'))

  {

    if(nofade)

    {

      document.getElementById('specialLayer_darkener').style.display = 'none';

    }

    else

    {

      var from = document.getElementById('specialLayer_darkener').myOpacVal;

      // console.info('Fading from ' + from);

      opacity('specialLayer_darkener', from, 0, 1000);

      setTimeout("document.getElementById('specialLayer_darkener').style.display = 'none';", 1000);

    }

  }

}