var _g_autoChangeEnabled = true;

function switchImage(srcimageid, newfilename)
{
	_g_autoChangeEnabled = false;
	changeAndFadeImage(srcimageid, newfilename);
}

function autoChangeImages(currentChild)
{
	if(_g_autoChangeEnabled == true)
	{
		var imagescontainer = document.getElementById("imagescontainer");
		
		if(imagescontainer != null)
		{
			var containerchildren = imagescontainer.getElementsByTagName('img');
			
			currentChild++;
			if(currentChild >= containerchildren.length)
				currentChild = 0;
				
			//alert(currentChild + ": " + containerchildren[currentChild].src);
			
			var command = 'autoChangeImages("' + currentChild + '");autoChangeAndFadeImage("bigimage","' + containerchildren[currentChild].src + '");';
			setTimeout(command, 9000);
		}
	}
}

function autoChangeAndFadeImage(srcimageid, newfilename)
{
	if(_g_autoChangeEnabled == true)
	{
		var srcimage = document.getElementById(srcimageid);

		if(srcimage != null)
		{			
			srcimage.style.opacity = 0.0;	
			srcimage.style.filter = 'alpha(opacity=0)';		
			srcimage.src = newfilename;
			
			//call fade out routine for secondimage on top
			setTimeout('autoFade("' + srcimageid + '")', 0);
		}
	}
}

function autoFade(srcimageid)
{
	if(_g_autoChangeEnabled == true)
	{
		var srcimage = document.getElementById(srcimageid);
		if(srcimage != null)
		{
			//fade until done
			if(srcimage.style.opacity < 1.0)
			{
				changeAndSetOpacity(srcimageid, 0.015);
				
				setTimeout('autoFade("' + srcimageid + '")', 40);
			}
			else //done, setup background to show identical as on top
			{
				imageparent_td = document.getElementById("ImageSpace");
				imageparent_td.style.backgroundImage = "url(" + srcimage.src + ")";				
				imageparent_td.style.backgroundRepeat = "no-repeat";
			}

		}
	}
}

function changeAndFadeImage(srcimageid, newfilename)
{
	var srcimage = document.getElementById(srcimageid);

	if(srcimage != null)
	{			
		srcimage.style.opacity = 0.0;	
		srcimage.style.filter = 'alpha(opacity=0)';		
		srcimage.src = newfilename;
		
		//call fade out routine for secondimage on top
		setTimeout('fade("' + srcimageid + '")', 0);
	}
}

function fade(srcimageid)
{
	var srcimage = document.getElementById(srcimageid);
	if(srcimage != null)
	{
		//fade until done
		if(srcimage.style.opacity < 1.0)
		{
			changeAndSetOpacity(srcimageid, 0.03);
			
			setTimeout('fade("' + srcimageid + '")', 40);
		}
		else //done, setup background to show identical as on top
		{
			imageparent_td = document.getElementById("ImageSpace");
			imageparent_td.style.backgroundImage = "url(" + srcimage.src + ")";				
			imageparent_td.style.backgroundRepeat = "no-repeat";
		}

	}	
}

function changeAndSetOpacity(srcimageid, changevalue)
{
	var srcimage = document.getElementById(srcimageid);
	if(srcimage != null)
	{
		//alert("before opacity change: " + srcimage.style.opacity);
		
		var alpha = parseFloat(srcimage.style.opacity);
		
		//alert("before alpha change: " + alpha);
		
		alpha = alpha + changevalue;
		
		//alert("after alpha change: " + alpha);
		
		if(alpha > 1.0)
			alpha = 1.0;
		else if(alpha < 0.0)
			alpha = 0.0;
			
		//alert("after alpha check: " + alpha);
		
		srcimage.style.opacity = alpha;
		srcimage.style.filter = 'alpha(opacity=' + (alpha * 100) + ')';
		
		//alert("after opacity change: " + srcimage.style.opacity);
	}
}