function wechseln_b () {
	if(document.getElementById("w_karte")){
		  if (document.getElementById("w_karte").className == "on") {
		    document.getElementById("w_karte").className = "";
		  } 
	}
	if(document.getElementById("bericht")){
		  if (document.getElementById("bericht").className != "on"){
			  document.getElementById("bericht").className = "on";
		  }
	}
}
function wechseln_k () {
	if(document.getElementById("bericht")){
  		if (document.getElementById("bericht").className == "on") {
    		document.getElementById("bericht").className = "";
  		}
  	} 
  	if(document.getElementById("w_karte")){
  		if (document.getElementById("w_karte").className != "on"){
  			document.getElementById("w_karte").className = "on";
	 	}
	}
  
}