var popup_height=300;

function slideshow_visible(obj)
{
	var height;
	var top =10;
		
	popup_height=document.getElementById(obj).offsetHeight
	
	if (document.documentElement)
	{
		theLeft = document.documentElement.scrollLeft;
		theTop = document.documentElement.scrollTop;
		height=document.documentElement.clientHeight;
	}
	else if (document.body)
	{
		theLeft = document.body.scrollLeft;
		theTop = document.body.scrollTop;
		height=document.body.clientHeight;
	}
	
	if(height>popup_height)
	{
		top=(height-popup_height)/2;
	}
	
	top=top+theTop;
	
	obj = document.getElementById(obj);
	obj.style.visibility =  'visible';
	obj.style.top = top + 'px' ;
}




function slideshow_close()
{
	obj = document.getElementById('slideshow');
	obj.style.visibility = 'hidden' ;
	document.getElementById('hide').style.visibility ='hidden';
	
}

function slideshow_title()
{
	var html="";	
	html+="Image " + (current_slide+1) + " of " + slides.length;	
	
	if(current_slide>0)
	{
		html+=" <a href=\"javascript:change_slide(" + (current_slide-1) + ")\">< Prev</a> ";
	}
	
	if(current_slide<(slides.length-1))
	{
		html+=" <a href=\"javascript:change_slide(" + (current_slide+1) + ")\">Next ></a> ";
	}
	
	document.getElementById('slideshow_title').innerHTML=html;

}



function start_slideshow(slide)
{
	change_slide(slide);
	slideshow_visible('slideshow');

	document.getElementById('hide').style.visibility ='visible';
	
	
}

function change_slide(slide)
{
	current_slide=slide;
	slideshow_title();
	
	var html="";
	if(slides[current_slide]['type']=='page')
	{
		slide_getpage(slides[current_slide]['address']);
	}
	
	if(slides[current_slide]['type']=='image')
	{
		 html="<img src=\"" + image_path + "/" + slides[current_slide]['address'] + "\">";
		 document.getElementById('slideshow_inner').innerHTML=html;	
	}
}


function slide_getpage(url)
{
	document.getElementById('slideshow_inner').innerHTML='<div align="center"><img src="/images/loading.gif"></div>'
	ajax.open("GET", url, true);
	ajax.onreadystatechange = slideshow_updateresponse;
	ajax.send(null);
}

function slideshow_updateresponse()
{
	 if (ajax.readyState == 4)
	 {	 	
	 	document.getElementById('slideshow_inner').innerHTML=ajax.responseText;	 	
	 }
}