function toggle_div(div_name) {
	if(document.getElementById(div_name).style.visibility == "visible"){
		document.getElementById(div_name).style.visibility = "hidden";
		document.getElementById(div_name).style.display = "none";
		document.getElementById('pfeil_'+div_name).setAttribute("src","modules/styles/webseite_grafiken/pfeil_rechts.gif");
		
	}else{
		document.getElementById(div_name).style.visibility = "visible";
		document.getElementById(div_name).style.display = "";
		document.getElementById('pfeil_'+div_name).setAttribute("src","modules/styles/webseite_grafiken/pfeil_unten.gif");
		
	}
}