function switch_tab(val, val2, val3){

	document.getElementById("tab_aktuelles").style.display = 'none';
	document.getElementById("tab_blog").style.display = 'none';
	document.getElementById("tab_calc").style.display = 'none';
	document.getElementById("tab_video").style.display = 'none';
	
	document.getElementById("tl-aktuelles").style.color = '';
	document.getElementById("tl-blog").style.color = '';
	document.getElementById("tl-calc").style.color = '';
	document.getElementById("tl-video").style.color = '';
	
	document.getElementById("tid-aktuelles").className = 'none';
	document.getElementById("tid-blog").className = 'none';
	document.getElementById("tid-calc").className = 'none';
	document.getElementById("tid-video").className = 'none';
	

	document.getElementById(val).style.display = 'block';
	document.getElementById(val2).className = 'home';
	document.getElementById(val3).style.color = '#ffffff';
	
	}