/* DIAPORAMA

Pour l'executer dans le webBLock, insérer :

<script type="text/javascript">
initSlideshow ( 'ID-de-la -table-contenant-les-images', [temps-entre-chaque-image], [temps-entre-chaque-transition-du-fondu], [Pas-du-fondu], [Largeur-Image] );
</script>

Les 4 derniers paramètres sont optionnels. exemples :

initSlideshow ( 'slideshow', 2000 );
initSlideshow ( 'slideshow', 3000, 40, 3, 300);

fonction principale*/
function initSlideshow (id, speed, shadeTime, shadeStep, height) {
		
	var diaporamaContainer = document.getElementById(id);
	if (!diaporamaContainer) return;
	
	var tableImg = diaporamaContainer.getElementsByTagName('table');
	if (!tableImg) return;
	
	tableImg[0].style.verticalAlign='top';
	tableImg[0].style.position='relative';
	tableImg[0].style.display='block';
	
	var allImgs = diaporamaContainer.getElementsByTagName('img');
	if (!allImgs) return;

	if (!speed) { speed=3000; }
	if (!shadeTime) { shadeTime=30; }
	if (!shadeStep) { shadeStep=3; }

	if (!height) {
		height=200;
	}
	
	for(var i=0; i<allImgs.length; i++) {
		allImgs[i].style.display='none';
		allImgs[i].style.left='0px';
		allImgs[i].style.top='0px';
		allImgs[i].style.position='absolute';
		allImgs[i].style.height=height+'px';
	}
	
	diaporamaContainer.style.verticalAlign='top';
	diaporamaContainer.style.position='relative';
	diaporamaContainer.style.display='block';
	diaporamaContainer.style.width='auto';
	diaporamaContainer.style.height=height+'px';
	
	allImgs[0].style.display='block';
	
	var currentIdx=0;
	setTimeout(defilImage, speed);

	function defilImage() {
		
		var lastIdx=currentIdx;
		currentIdx++
		if (currentIdx==allImgs.length) { currentIdx=0; }

		var currentImg=allImgs[currentIdx];
		var lastImg=allImgs[lastIdx];
		
		currentImg.style.display='block';
		
		var opa=0;
		setNewOpacity();
		
		function setNewOpacity() {

			currentImg.style.opacity = opa/100;	
			lastImg.style.opacity = 1-opa/100;	
			
			currentImg.style.filter = 'alpha(opacity='+opa+');';	
			lastImg.style.filter = 'alpha(opacity='+(100-opa)+');';
			
			opa+=shadeStep;
			
			if (opa <= 100) { setTimeout (setNewOpacity, shadeTime); }
	
			else {
			lastImg.style.display='none';
			setTimeout(defilImage, speed);
			}
		}	
	}
}