var sl_nextImage = 1;
var sl_currImage = 0;
var sl_imageWidth = 456;
var sl_imageHeight = 342;
var sl_imageTimeout = 5000;
var sl_titleSpan ;
var sl_creditTo;
var sl_galleryShowing ;
var sl_playing = false ;
var sl_forward = true ;
var sl_pausePalyImg ;
var sl_startFading_timeout ;
var sl_opacityInterval = 5 ;
var sl_current ;

function sl_ImageInfo(iURL,iAlt,iTitle,credits)
{
	this.imageTitle = iTitle;
	this.imageAlt = iAlt;
	this.imageURL = iURL;
	this.credits = credits; 
}

function sl_slideShowLoad() {

	sl_creditTo = document.getElementById('sl_creditTo');
	sl_titleSpan = document.getElementById('sl_titleSpan');
	sl_galleryShowing = document.getElementById('galleryShowing');
	sl_pausePalyImg = document.getElementById('sl_pause_paly_img');
	
  	var el = document.getElementById('fading_image_container');
  	while (el.firstChild) { el.removeChild(el.firstChild); }

  	el.style.width = sl_imageWidth + 'px';
  	el.style.height = sl_imageHeight + 'px';

  	for(var i=0; i<sl_sliderArray.length; i++) {

    	var t = document.createElement('img');

    	t.setAttribute('src',sl_sliderArray[i].imageURL);
    	t.setAttribute('width',sl_imageWidth);
    	t.setAttribute('height',sl_imageHeight);
    	t.style.position = 'absolute';
    	t.style.visibility = 'hidden';
    	t.title = sl_sliderArray[i].imageTitle ;
    	t.alt = sl_sliderArray[i].imageAlt ;
    	el.appendChild(t);
  	}
  	sl_updateTitle(el.firstChild.title)
  	el.firstChild.style.visibility = 'visible';
  	sl_current = el.firstChild;
  	sl_playing = true ;
  	sl_startFading_timeout = window.setTimeout(sl_startFading, sl_imageTimeout );
}

function sl_startFading() {
  var el = document.getElementById('fading_image_container').childNodes[sl_nextImage];
  el.style.visibility = 'visible';
  el.style.zIndex = 2;
  sl_setOpacity(el, 0);
  sl_fadeImage(el,0);
  sl_currImage = sl_nextImage ;
  sl_nextImage = (sl_nextImage < sl_sliderArray.length-1) ? sl_nextImage + 1 : 0;
 
}

function sl_fadeImage(el, currentOpacity) {

  currentOpacity += sl_opacityInterval;
  if (currentOpacity > 100) {
  	sl_updateTitle(el.title);//alert();
    sl_setOpacity(el, 100);
    

    
	sl_current.style.visibility = 'hidden';
	sl_current = el ;
	
    el.style.zIndex = 1;
    if( sl_playing == true ) {
    	sl_startFading_timeout = window.setTimeout(sl_startFading, sl_imageTimeout);
    }
    
  }
  else {
    sl_setOpacity(el, currentOpacity);
    window.setTimeout(function() { sl_fadeImage(el, currentOpacity); }, 50);
  }
}

function sl_setOpacity(el, opacity) {
	opacity /= 100;
	el.style.opacity = opacity;
	el.style.MozOpacity = opacity;
	el.style.filter = "alpha(opacity=" + (opacity*100) + ")";
}

function sl_updateTitle(title){
	sl_titleSpan.innerHTML=title;
	sl_creditTo.innerHTML = "Photo: " +  sl_sliderArray[sl_currImage].credits;
	var imageNum = sl_nextImage == 0 ? sl_sliderArray.length : sl_nextImage ;
	sl_galleryShowing.innerHTML = 'Showing '+imageNum+' of '+sl_sliderArray.length ; 
	
}

function sl_paly(){
	sl_pausePalyImg.src = imageRoot + '/images/gallery_pause.png' ;
	sl_playing = true ;
	sl_opacityInterval = 5 ;
	sl_startFading();
	
}

function sl_pause(){
	window.clearTimeout(sl_startFading_timeout);
	sl_pausePalyImg.src = imageRoot + '/images/gallery_play.png' ;
	sl_playing = false ;
	sl_opacityInterval = 10 ;
}

function sl_next(){
	sl_pause();
	if(sl_sliderArray.length<2){return;}
	sl_forward = true ;
	sl_startFading();
}

function sl_previuos(){
	sl_pause();//sl_sliderArray.length-1
	if(sl_sliderArray.length<2){return;}
	sl_forward = false ;
	sl_nextImage = ( sl_nextImage == 0 ) ? sl_sliderArray.length-1 : sl_nextImage-1;
	sl_nextImage = ( sl_nextImage == 0 ) ? sl_sliderArray.length-1 : sl_nextImage-1;
	sl_startFading();
}

function sl_showRand(index){
	if(sl_sliderArray.length<2){return;}
	if(index==sl_currImage){return;}

	sl_nextImage = index ;
	sl_pause();//sl_sliderArray.length-1
	sl_forward = true ;
	sl_startFading();
}

function sl_pause_paly(){
	if (sl_playing == true ){
		sl_pause();
	}else{
		sl_forward = true ;
		sl_paly();
	}
}

function sl_scrollToplace(){
	if(document.all){
		window.scrollTo( document.body.scrollLeft , 110 );
	}else{
		window.scrollTo( window.pageXOffset, 110 );
	}
}