//Variablen:
var bgImages = new Array(
	'bg-01.jpg',
	'bg-02.jpg',
	'bg-04.jpg',
	'bg-05.jpg'
);
var bgImagesCount = bgImages.length;
var bgImagesIndex = Math.round(Math.random()*(bgImagesCount-1));

function changeCSS(cssEigenschaft, cssValue, cssObject) {
	eval("$(cssObject).css({ '" + cssEigenschaft + "':'" + cssValue + "' });");
}