//Rohe Fassung des Skriptes
//------------------------------------------------
//EINSTELLUNGEN

var updateinterval = 100  //Aktualisierungsrate in Millisekunden

var imgSrc="images/design/back_01.jpg" //Hintergrundbild angeben

var centerIt = 0 // 1 = zentrieren, 0 = linksbündig setzen


//------------------------------------------------
//------------------------------------------------
//------------------------------------------------


//------------------------------------------------
//Fenstergröße ermitteln
function getWinSize() {
    var myWidth = 0, myHeight = 0;
 
    if( typeof( window.innerWidth ) == 'number' ) {
        //Non-IE
        myWidth = window.innerWidth;
        myHeight = window.innerHeight;
    } else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
        //IE 6+ in 'standards compliant mode'
        myWidth = document.documentElement.clientWidth;
        myHeight = document.documentElement.clientHeight;
    } else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
        //IE 4 compatible
        myWidth = document.body.clientWidth;
        myHeight = document.body.clientHeight;
    }
    return [ myWidth, myHeight ];
}

//------------------------------------------------
//Bildgröße ermitteln
function getImgSize(){
 	
	var newImage = new Image();
	
	newImage.onload = function (){
		getHeightWidth( this )
	};
	
	newImage.src = imgSrc;
	
	newImageSize = getHeightWidth( newImage );
			
	return newImageSize;
	
}
	
function getHeightWidth( newImage ){

   var breite = 0, hoehe = 0;
   
	if (newImage.alreadyLoaded || newImage.width == 0)
		return true;
	breite = newImage.width;
	hoehe = newImage.height;
	//newImage.alreadyLoaded = true;
	
			
	return [ breite, hoehe ];
	
	
}

//------------------------------------------------
//Hintergrund anpassen 
function setbg(){
	theWinWidth = getWinSize()[0]
	theWinHeight = getWinSize()[1]
	
	theImgWidth = getImgSize()[0]
	theImgHeight = getImgSize()[1]
	
	winratio = theWinWidth/theWinHeight
	imgratio = theImgWidth/theImgHeight
	
	
	//ausgabestring = "winratio = " + winratio + " imgratio = " + imgratio + "   " +theImgWidth + " x " + theImgHeight
	

	

	
	if(winratio>=imgratio){
		document.getElementById("bg_image").style.width = (theWinWidth)+"px";
		document.getElementById("bg_image").style.height = "auto";		
	}else{	
		document.getElementById("bg_image").style.height = theWinHeight+"px";
		document.getElementById("bg_image").style.width = "auto";		
	}
	
	//wenn Bild zentriert werden soll
	if (centerIt ==1){
		aktwidth = document.getElementById("bg_image").width // aktuelle Bildgröße ermitteln
		
		if(aktwidth>theWinWidth){
			document.getElementById("bg").style.marginLeft = ((theWinWidth-aktwidth)/2)+"px"
		}else{
			document.getElementById("bg").style.marginLeft = "0"
		}
	}
}

//------------------------------------------------
//Hintergrund anpassen wiederholen
function startIt(){	


	var aktiv = window.setInterval('setbg()', updateinterval);	
}

//------------------------------------------------
//Hintergrund anpassen bei Fensteränderung starten 
window.onresize = startIt

//------------------------------------------------
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