/** slideshow **/

function initSlideshow(elImg, elText, feed)
{
    var slideshowObj = {
	img : null,
	txt : null,
	request : null,
	sfeed : feed,
	arImages : null,
	arDescs : null,
	arIdx : 0,
	onSwitch : function()
	{
	    slideshowObj.img.src = arImages[slideshowObj.arIdx];
	    slideshowObj.txt.innerHTML = arDescs[slideshowObj.arIdx];

	    if( ++slideshowObj.arIdx >= arImages.length ) slideshowObj.arIdx = 0;
	    window.setTimeout( slideshowObj.onSwitch, 10000 );
	},
	onResult : function()
	{
	    if( (slideshowObj.request.readyState == 4) &&
		(slideshowObj.request.status==200 || window.location.href.indexOf("http")==-1))
	    {
		if( !slideshowObj.request.responseXML ) {
		    return;
		}
	
		arImages = new Array();
		arDescs = new Array();

		var slides = slideshowObj.request.responseXML.documentElement.getElementsByTagName( "image" );

		for( var j = 0; j < slides.length; j ++ ) {
		    var url = slides[j].getAttribute( "url" );
		    var desc = slides[j].getAttribute( "desc" );
		    arImages[j] = url;
		    arDescs[j] = desc;
		}

		window.setTimeout( slideshowObj.onSwitch, 5000 );
            }
	},
	start : function()
	{
	    slideshowObj.img = document.getElementById( elImg );
	    if( !slideshowObj.img ) return;
	    slideshowObj.txt = document.getElementById( elText );
	    if( !slideshowObj.txt ) return;

	    if (window.XMLHttpRequest)
		slideshowObj.request = new XMLHttpRequest()
	    else if (window.ActiveXObject)
	    {
		try {
		    slideshowObj.request = new ActiveXObject("Msxml2.XMLHTTP")
		} catch (e){
		    try{
			slideshowObj.request = new ActiveXObject("Microsoft.XMLHTTP")
		    } catch (e){}
		}
	    }
	    else {
		return ;
	    }

	    var url = feed;
	    slideshowObj.request.onreadystatechange=slideshowObj.onResult;
	    slideshowObj.request.open( "GET", url, true );
	    slideshowObj.request.send( null );
	}
    };

    return slideshowObj;
}