function galerie(richtung, string, galerie) {
if(richtung == "preload"){
	a = string;
}
else
{
array_bilder = string.split(',');
count_array_bilder = array_bilder.length;

if(richtung == "next"){
	a = Number(a)+1;
	if(a == count_array_bilder){
	a = Number(count_array_bilder)-1;
	}
}

if(richtung == "pre"){
	a = Number(a)-1;
	if(a < 0){
	a = "0";
	}
}
bild_zahl = Number(a)+1;
document.getElementById('img_vorschau').src= "galerie/"+galerie+"/"+array_bilder[a];
document.getElementById('bild_zaehler').innerHTML= "Bild "+bild_zahl+" von "+count_array_bilder;
}
}