function oeffnen(punkt) {
	document.getElementById(punkt).style.visibility="visible";
}

function schliessen() {
	for (var i = 0; i <= 30; i++){
		var id = "M"+i;
		try {
    		document.getElementById(id).style.visibility="hidden";
	  	} catch (e) {

	  	}
	}
}

function roll_in(id) {
	document.getElementById(id).style.backgroundColor="#eaeaea";
}

function roll_out(id) {
	document.getElementById(id).style.backgroundColor="#bf0000";
}