//dies ist korrekt, wenn onload alle blocks unsichtbar sein sollen
function switchLayer(n) {
	var e = document.getElementById(n);
	if (e==null) return;
	if( e.style.display == "block" ) {
		e.style.display = "none";
	} else {
		e.style.display = "block";
	}
}

// Umschaltung um alle screens anzuzeigen
var screenVisibility = 0;
opblocks = new Array("jazzTD", "bigbandTD", "audiobookTD", "popTD", "singerTD", "kabarettTD", "mundartTD", "crossoverTD", "kammermusikTD", "hoerspielTD");

function showScreens () {
	if (screenVisibility == 0) {
		  for (var i = 0; i < opblocks.length; i++) {
			document.getElementById(opblocks[i]).style.display = "block";
			n = opblocks[i];	
		}
		screenVisibility = 1;
	}
	else {
		  for (var i = 0; i < opblocks.length; i++) {
			document.getElementById(opblocks[i]).style.display = "none";
			n = opblocks[i];		
		}	
		screenVisibility = 0;	  
	}
}