function opacity(id, opacStart, opacEnd, millisec) {
	//speed for each frame
	var speed = Math.round(millisec / 100);
	var timer = 0;
	if(sp = document.getElementById("startanimation")){
		
		//determine the direction for the blending, if start and end are the same nothing happens
		if(opacStart > opacEnd) {
			for(i = opacStart; i >= opacEnd; i--) {
				setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
				timer++;
			}
			setTimeout("sp.parentNode.removeChild(sp)",600);
	
		} else if(opacStart < opacEnd) {
			setdivlayer = document.getElementById("container").style; 
			setdivlayer.display = "block";

			for(i = opacStart; i <= opacEnd; i++)
				{
				setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
				timer++;
			}
		}
	}
	else
	{
		if(opacStart > opacEnd) {
			for(i = opacStart; i >= opacEnd; i--) {
				setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
				timer++;
			}
		} else if(opacStart < opacEnd) {
			for(i = opacStart; i <= opacEnd; i++)
				{
				setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
				timer++;
			}
		}

	}
}


//change the opacity for different browsers
function changeOpac(opacity, id) {
	var object = document.getElementById(id).style; 
	object.opacity = (opacity / 100);
	object.MozOpacity = (opacity / 100);
	object.KhtmlOpacity = (opacity / 100);
	object.filter = "alpha(opacity=" + opacity + ")";
}

function shiftOpacity(id, millisec) {
	//if an element is invisible, make it visible, else make it ivisible
	if(document.getElementById(id).style.opacity == 0) {
		opacity(id, 0, 100, millisec);
	} else {
		opacity(id, 100, 0, millisec);
	}
}

function blendimage(divid, imageid, imagefile, millisec) {
	var speed = Math.round(millisec / 100);
	var timer = 0;
	
	//set the current image as background
	document.getElementById(divid).style.backgroundImage = "url(" + document.getElementById(imageid).src + ")";
	
	//make image transparent
	changeOpac(0, imageid);
	
	//make new image
	document.getElementById(imageid).src = imagefile;

	//fade in image
	for(i = 0; i <= 100; i++) {
		setTimeout("changeOpac(" + i + ",'" + imageid + "')",(timer * speed));
		timer++;
	}
}

function currentOpac(id, opacEnd, millisec) {
	//standard opacity is 100
	var currentOpac = 100;
	
	//if the element has an opacity set, get it
	if(document.getElementById(id).style.opacity < 100) {
		currentOpac = document.getElementById(id).style.opacity * 100;
	}

	//call for the function that changes the opacity
	opacity(id, currentOpac, opacEnd, millisec)
}

function displayDiv(){
	opacity('navtext', 0, 100, 3000);
}

function hideDiv(){
	opacity('navtext', 100, 0, 1000);
}
			
function displayNavText ( text ) {

	if(document.getElementById(text))
	{
		if(document.getElementById(text).style.opacity == 0)
		{
			changeOpac(0, "text_Leistungen");
			changeOpac(0, "text_Ansprechpartner");
			changeOpac(0, "text_Spektrum");
			changeOpac(0, "text_Information");
			changeOpac(0, "text_Kontakt");
			changeOpac(0, "text_News");
			changeOpac(0, "text_Impressum");
			opacity(text, 0, 100, 600);
		}
	}
}

function hideNavText ( text ) {
	if(document.getElementById(text))
	{
		if(document.getElementById(text).style.opacity == 1)
		{
		opacity(text, 100, 0, 300);
		}
		else
		{
			changeOpac(0, "text_Leistungen");
			changeOpac(0, "text_Ansprechpartner");
			changeOpac(0, "text_Spektrum");
			changeOpac(0, "text_Information");
			changeOpac(0, "text_Kontakt");
			changeOpac(0, "text_News");
			changeOpac(0, "text_Impressum");
		}
	}
}

function aloaded(){		
	setTimeout("opacity('startanimation', 100, 0, 500)", 13500);							 
	setTimeout("opacity('container', 0, 100, 500)", 13500);							 
}