var extension = ".gif";
var prefix = "grafik/bttn_";

var current = Array( imgNames.length);
var counter = Array( imgNames.length);
var img_on = Array( imgNames.length);
var img_off = Array( imgNames.length);
            
function preLoad()
{
	for( i=0; i<imgNames.length; i++)
	{
		img_on[i] = Array( imgNames[i].length);
		img_off[i] = Array( imgNames[i].length);
		current[i] = 0;
		counter[i] = 0;
		for( j=0; j<imgNames[i].length; j++)
		{
			img_off[i][j] = new Image();
			img_off[i][j].src = prefix + imgNames[i][j] + "_off" + extension;
			img_on[i][j] = new Image();
			img_on[i][j].src = prefix + imgNames[i][j] + extension;
		}
	}
}

function imgOn( imgName)
{
	level = getLevel( imgName);
	if( imgName != siteActive[level])
		activeOff( level);
	if( imgName != "")
	{
		document[imgName].src=prefix + imgName + extension;
	}
	current[level] = 1;
}

function imgOff( imgName)
{
	var level = getLevel( imgName);
	if( imgName != siteActive[level])
	{
		document[imgName].src=prefix + imgName + "_off" + extension;
		counter[level]++;
		setTimeout( "activeOn( " + level+ ")", 300);
	}
	current[level] = 0;
}

function activeOn( level)
{
	if( --counter[level]>0)
		return;
	counter[level] = 0;
	if( current[level])
		return;
	var imgName = siteActive[level];
	if( imgName)
		document[imgName].src = prefix + imgName + extension;
}

function activeOff( level)
{
	var imgName = siteActive[level];
	if( imgName)
		document[imgName].src = prefix + imgName + "_off" + extension;
	
}


function getLevel( imgName)
{
	for( i=0; i<imgNames.length; i++)
	{
		for( j=0; j<imgNames[i].length; j++)
		{
			if( imgNames[i][j] == imgName)
			{
				return i;
			}
		}
	}
	alert( "FEHLER: " + imgName + " nicht in den imgNames gefunden");
}