function init_slide()
{
  
  slideShow_total_images = photoSlide.length;
  slideShow_cur_image = 0;
  slideShow_last = 3;
  slideShow_changed = false;
  
  slideNavButtonColor = new Array;
  
  slideShow();
  
}

function slideShow()
{
  
  document.getElementById('photos').style.backgroundImage = "url('"+photoSlide[slideShow_cur_image]+"')";  
  document.getElementById('slide_nav_button_'+slideShow_cur_image).style.backgroundColor = "#579C0C";
  
  if(!slideShow_changed)
  {
    document.getElementById('slide_nav_button_'+slideShow_last).style.backgroundColor = "#666666";
	slideNavButtonColor[slideShow_last] = "#666666";
  }
  
  slideShow_last = slideShow_cur_image;
  
  if(slideShow_cur_image == photoSlide.length - 1)
  {
    slideShow_cur_image = 0;
  } else {
    slideShow_cur_image += 1;
  }
  
  redoSlideShow();
  
}

function redoSlideShow()
{
  
  if(!slideShow_changed)
  {
    setTimeout("slideShow();",10000);
  }
  
  slideShow_changed = false;
  
}

function changeSlideImage(identifier)
{
  
  document.getElementById('slide_nav_button_'+slideShow_last).style.backgroundColor = "#666666";
  
  slideShow_last = slideShow_cur_image;
  slideShow_cur_image = identifier;
  slideShow_changed = true;
  
  slideNavButtonColor[identifier] = "#579C0C";
  
  slideShow();
  
}

function showPhotoBig(url)
{
  
  div = document.getElementById('photoDiv');
  
  
}

function projectsPhotoChange()
{
  
  div = document.getElementById('projectsPhoto');
  
  photos = new Array();
  photos[0] = "/images/photos/projects/Dredgingsystem hs Albatros.jpg";
  photos[1] = "/images/photos/projects/Grossglockner base station.jpg";
  photos[2] = "/images/photos/projects/Grossglockner dregingsystem.jpg";
  photos[3] = "/images/photos/projects/seine.jpg";
  
  if((curPhoto + 1) == photos.length)
  {
    curPhoto = 0;
  } else {
    curPhoto += 1;
  }
  
  div.innerHTML = '<img src="'+photos[curPhoto]+'" alt="Projects">';
  
  setTimeout('projectsPhotoChange();',5000);
  
}

// De functie "getAbsolutePosition();" is geschreven door Matt  Kruse (http://www.javascripttoolbox.com/lib/objectposition/index.php)
function getAbsolutePosition(o) {
    var fixBrowserQuirks = true;
      // If a string is passed in instead of an object ref, resolve it
    if (typeof(o)=="string") {
      o = resolveObject(o);
    }
    
    if (o==null) {
      return null;
    }
    
    var left = 0;
    var top = 0;
    var width = 0;
    var height = 0;
    var parentNode = null;
    var offsetParent = null;
  
    
    offsetParent = o.offsetParent;
    var originalObject = o;
    var el = o; // "el" will be nodes as we walk up, "o" will be saved for offsetParent references
    while (el.parentNode!=null) {
      el = el.parentNode;
      if (el.offsetParent==null) {
      }
      else {
        var considerScroll = true;
        /*
        In Opera, if parentNode of the first object is scrollable, then offsetLeft/offsetTop already 
        take its scroll position into account. If elements further up the chain are scrollable, their 
        scroll offsets still need to be added in. And for some reason, TR nodes have a scrolltop value
        which must be ignored.
        */
        if (fixBrowserQuirks && window.opera) {
          if (el==originalObject.parentNode || el.nodeName=="TR") {
            considerScroll = false;
          }
        }
        if (considerScroll) {
          if (el.scrollTop && el.scrollTop>0) {
            top -= el.scrollTop;
          }
          if (el.scrollLeft && el.scrollLeft>0) {
            left -= el.scrollLeft;
          }
        }
      }
      // If this node is also the offsetParent, add on the offsets and reset to the new offsetParent
      if (el == offsetParent) {
        left += o.offsetLeft;
        if (el.clientLeft && el.nodeName!="TABLE") { 
          left += el.clientLeft;
        }
        top += o.offsetTop;
        if (el.clientTop && el.nodeName!="TABLE") {
          top += el.clientTop;
        }
        o = el;
        if (o.offsetParent==null) {
          if (o.offsetLeft) {
            left += o.offsetLeft;
          }
          if (o.offsetTop) {
            top += o.offsetTop;
          }
        }
        offsetParent = o.offsetParent;
      }
    }
    
  
    if (originalObject.offsetWidth) {
      width = originalObject.offsetWidth;
    }
    if (originalObject.offsetHeight) {
      height = originalObject.offsetHeight;
    }
    
    return {'left':left, 'top':top, 'width':width, 'height':height
        };
  };
  
function rollovernavShow(from_div,to_obj)
{
    
	rollovernavHide();
	
    pos = getAbsolutePosition(to_obj);
	div = document.getElementById('rollovernav');
	contents = document.getElementById(from_div).innerHTML;
	
	// Some nasty but necessary quirks have to be solved depending on the browser, sorry to all the standards fanatics out there...
	if (navigator.userAgent.search('Firefox') >= 0) { // Checking if the browser is Firefox (other Gecko-based browsers don't have this quirk)
	  div.style.visibility = 'visible';
	  div.style.top = pos.top + to_obj.offsetHeight + 'px';
	  div.style.left = pos.left - 1 + 'px';
	  div.innerHTML = contents;	
	} else if(navigator.userAgent.search('MSIE 8.') == -1){ // Checking if it's another browser that's not IE8 (probably IE7 an lower)
	  div.style.visibility = 'visible';
	  div.style.top = pos.top + to_obj.offsetHeight + 'px';
	  div.style.left = pos.left + 'px';
	  div.innerHTML = contents;
	} else { // If the rest is false, the browser must be IE8
	  div.style.visibility = 'visible';
	  div.style.top = pos.top + to_obj.offsetHeight + 2 + 'px';
	  div.style.left = pos.left + 2 + 'px';
	  div.innerHTML = contents;
	}
	
	to_obj.style.backgroundImage = 'url(/images/1px_59pc_black.png)';
	to_obj.style.color = '#579C0C';
	
	last_rollover = to_obj;
		
}

function rollovernavHide()
{
  
  div = document.getElementById('rollovernav');
  
  div.style.visibility = 'hidden';
  div.style.top = '0px';
  div.style.left = '0px';
  div.innerHTML = '';
  
  if(typeof last_rollover != 'undefined')
  {  
    last_rollover.style.backgroundImage = '';
    last_rollover.style.color = '#ffffff';
  }
  
}

function planRollHide(step)
{
  
  if(step == 1)
  {
    setTimeout('planRollHide(2);',0.1);
	continueRollHide = true;
  } else if (step == 2 && continueRollHide) {
  	rollovernavHide();
  }
  
}

function scrolldown()
{
  
  contentblock_pos = getAbsolutePosition(document.getElementById('contentblock'));
  window.scrollBy(0,contentblock_pos.top);
  
}