function menu(id) {
  if(id == 1) {
    if(document.getElementById('subnavi_1').style.display == 'none') {
      document.getElementById('subnavi_1').style.display = 'block';
    }
    document.getElementById('subnavi_2').style.display = 'none';
    document.getElementById('subnavi_3').style.display = 'none';
    document.getElementById('subnavi_4').style.display = 'none';
	document.getElementById('aNews').className = 'aktiv';
	document.getElementById('aAbout').className = '';
	document.getElementById('aMedia').className = '';
	document.getElementById('aComm').className = '';
  } else if(id == 2) {
    if(document.getElementById('subnavi_2').style.display == 'none') {
      document.getElementById('subnavi_2').style.display = 'block';
    }
    document.getElementById('subnavi_1').style.display = 'none';
    document.getElementById('subnavi_3').style.display = 'none';
    document.getElementById('subnavi_4').style.display = 'none';
	document.getElementById('aNews').className = '';
	document.getElementById('aAbout').className = 'aktiv';
	document.getElementById('aMedia').className = '';
	document.getElementById('aComm').className = '';
  } else if(id == 3) {
    if(document.getElementById('subnavi_3').style.display == 'none') {
      document.getElementById('subnavi_3').style.display = 'block';
    }
    document.getElementById('subnavi_1').style.display = 'none';
    document.getElementById('subnavi_2').style.display = 'none';
    document.getElementById('subnavi_4').style.display = 'none';
	document.getElementById('aNews').className = '';
	document.getElementById('aAbout').className = '';
	document.getElementById('aComm').className = 'aktiv';
	document.getElementById('aMedia').className = '';
  } else if(id == 4) {
    if(document.getElementById('subnavi_4').style.display == 'none') {
      document.getElementById('subnavi_4').style.display = 'block';
    }
    document.getElementById('subnavi_1').style.display = 'none';
    document.getElementById('subnavi_2').style.display = 'none';
	document.getElementById('subnavi_3').style.display = 'none';
	document.getElementById('aNews').className = '';
	document.getElementById('aAbout').className = '';
	document.getElementById('aComm').className = '';
	document.getElementById('aMedia').className = 'aktiv';
  }
}

function screensize () {
	if (screen.width > 1024) {
	  document.getElementById('wrapper').className = "site_big";
	} else {
	  document.getElementById('wrapper').className = "site_1024";
	}
}

//rechter pfeil
function galbox_up () {
  var padding = document.getElementById('galboximages').style.marginTop;
  var padding = padding.replace(/px/, '');
  padding *= 1;
  if(padding > ((Math.ceil(document.getElementById('galboximages').getElementsByTagName("div").length / 4) * 90) * -1) +71) {
    document.getElementById('galboximages').style.marginTop = padding - 180 + 'px';
  }
}
//linker pfeil
function galbox_down () {
  var padding = document.getElementById('galboximages').style.marginTop;
  var padding = padding.replace(/px/, '');
  padding *= 1;
  if(padding < 0) {
    document.getElementById('galboximages').style.marginTop = padding + 180 + 'px';
  }
}