function runde(x, n) {
  if (n < 1 || n > 14) return false;
  var e = Math.pow(10, n);
  var k = (Math.round(x * e) / e).toString();
  if (k.indexOf('.') == -1) k += '.';
  k += e.toString().substring(1);
  return k.substring(0, k.indexOf('.') + n+1);
}

function isInt(x) {
   var y=parseInt(x);
   if (isNaN(y)) return false;
   return x==y && x.toString()==y.toString();
 } 

function calculate(bibershop) {

	if(document.bibershop.art1.value!="" && !isInt(document.bibershop.art1.value)){
			document.bibershop.art1.value="";
			document.bibershop.summe1.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art2.value!="" && !isInt(document.bibershop.art2.value)){
			document.bibershop.art2.value="";
			document.bibershop.summe2.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art3.value!="" && !isInt(document.bibershop.art3.value)){
			document.bibershop.art3.value="";
			document.bibershop.summe3.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art4.value!="" && !isInt(document.bibershop.art4.value)){
			document.bibershop.art4.value="";
			document.bibershop.summe4.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art10.value!="" && !isInt(document.bibershop.art10.value)){
			document.bibershop.art10.value="";
			document.bibershop.summe10.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art15.value!="" && !isInt(document.bibershop.art15.value)){
			document.bibershop.art15.value="";
			document.bibershop.summe15.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art20.value!="" && !isInt(document.bibershop.art20.value)){
			document.bibershop.art20.value="";
			document.bibershop.summe20.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art22.value!="" && !isInt(document.bibershop.art22.value)){
			document.bibershop.art22.value="";
			document.bibershop.summe22.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art23.value!="" && !isInt(document.bibershop.art23.value)){
			document.bibershop.art23.value="";
			document.bibershop.summe23.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art25.value!="" && !isInt(document.bibershop.art25.value)){
			document.bibershop.art25.value="";
			document.bibershop.summe25.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art28.value!="" && !isInt(document.bibershop.art28.value)){
			document.bibershop.art28.value="";
			document.bibershop.summe28.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}	
	if(document.bibershop.art32.value!="" && !isInt(document.bibershop.art32.value)){
			document.bibershop.art32.value="";
			document.bibershop.summe32.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art35.value!="" && !isInt(document.bibershop.art35.value)){
			document.bibershop.art35.value="";
			document.bibershop.summe35.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art38.value!="" && !isInt(document.bibershop.art38.value)){
			document.bibershop.art38.value="";
			document.bibershop.summe38.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art42.value!="" && !isInt(document.bibershop.art42.value)){
			document.bibershop.art42.value="";
			document.bibershop.summe42.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art45.value!="" && !isInt(document.bibershop.art45.value)){
			document.bibershop.art45.value="";
			document.bibershop.summe45.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art48.value!="" && !isInt(document.bibershop.art48.value)){
			document.bibershop.art48.value="";
			document.bibershop.summe48.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art50.value!="" && !isInt(document.bibershop.art50.value)){
			document.bibershop.art50.value="";
			document.bibershop.summe50.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art52.value!="" && !isInt(document.bibershop.art52.value)){
			document.bibershop.art52.value="";
			document.bibershop.summe52.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art56.value!="" && !isInt(document.bibershop.art56.value)){
			document.bibershop.art56.value="";
			document.bibershop.summe56.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art61.value!="" && !isInt(document.bibershop.art61.value)){
			document.bibershop.art61.value="";
			document.bibershop.summe61.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}
	if(document.bibershop.art62.value!="" && !isInt(document.bibershop.art62.value)){
			document.bibershop.art62.value="";
			document.bibershop.summe62.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}	
	if(document.bibershop.art70.value!="" && !isInt(document.bibershop.art70.value)){
			document.bibershop.art70.value="";
			document.bibershop.summe70.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}	
	if(document.bibershop.art71.value!="" && !isInt(document.bibershop.art71.value)){
			document.bibershop.art71.value="";
			document.bibershop.summe71.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}	
	if(document.bibershop.art74.value!="" && !isInt(document.bibershop.art74.value)){
			document.bibershop.art74.value="";
			document.bibershop.summe74.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}	
	if(document.bibershop.art75.value!="" && !isInt(document.bibershop.art75.value)){
			document.bibershop.art75.value="";
			document.bibershop.summe75.value="";
			alert('Bitte nur ganze Zahlen eingeben.');
			return false;
	}		
	
	
	document.bibershop.summe1.value = document.bibershop.art1.value*1.10;
	document.bibershop.summe2.value = document.bibershop.art2.value*1.10;
	document.bibershop.summe3.value = document.bibershop.art3.value*6.10;
	document.bibershop.summe4.value = document.bibershop.art4.value*2.10;
	document.bibershop.summe10.value = document.bibershop.art10.value*6.00;
	document.bibershop.summe15.value = document.bibershop.art15.value*13.00;
	document.bibershop.summe20.value = document.bibershop.art20.value*8.00;	
	document.bibershop.summe22.value = document.bibershop.art22.value*15.00;	
	document.bibershop.summe23.value = document.bibershop.art23.value*16.50;	
	document.bibershop.summe25.value = document.bibershop.art25.value*16.00;
	document.bibershop.summe28.value = document.bibershop.art28.value*27.50;
	document.bibershop.summe32.value = document.bibershop.art32.value*6.50;
	document.bibershop.summe35.value = document.bibershop.art35.value*11.00; 
	document.bibershop.summe38.value = document.bibershop.art38.value*17.50;
	document.bibershop.summe42.value = document.bibershop.art42.value*19.50;
	document.bibershop.summe45.value = document.bibershop.art45.value*31.00;
	document.bibershop.summe48.value = document.bibershop.art48.value*54.00;	
	document.bibershop.summe50.value = document.bibershop.art50.value*1.80;	
	document.bibershop.summe52.value = document.bibershop.art52.value*8.50;	
	document.bibershop.summe56.value = document.bibershop.art56.value*8.50;
	document.bibershop.summe61.value = document.bibershop.art61.value*5.00;	
	document.bibershop.summe62.value = document.bibershop.art62.value*8.00;
	document.bibershop.summe70.value = document.bibershop.art70.value*3.90;	
	document.bibershop.summe71.value = document.bibershop.art71.value*7.50;
	document.bibershop.summe74.value = document.bibershop.art74.value*4.00;
	document.bibershop.summe75.value = document.bibershop.art75.value*7.50;	
	
	
	theValue = document.bibershop.art1.value*1.10 
		+ document.bibershop.art2.value*1.10 
		+ document.bibershop.art3.value*6.10		
		+ document.bibershop.art4.value*2.10		
		+ document.bibershop.art10.value*6.00
		+ document.bibershop.art15.value*13.00
		+ document.bibershop.art20.value*8.00
		+ document.bibershop.art22.value*15.00
		+ document.bibershop.art23.value*16.50
		+ document.bibershop.art25.value*16.00
		+ document.bibershop.art28.value*27.50
		+ document.bibershop.art32.value*6.50
		+ document.bibershop.art35.value*11.00
		+ document.bibershop.art38.value*17.50
		+ document.bibershop.art42.value*19.50
		+ document.bibershop.art45.value*31.00
		+ document.bibershop.art48.value*54.00
		+ document.bibershop.art50.value*1.80
		+ document.bibershop.art52.value*8.50
		+ document.bibershop.art56.value*8.50
		+ document.bibershop.art61.value*5.00
		+ document.bibershop.art62.value*8.00
		+ document.bibershop.art70.value*3.90
		+ document.bibershop.art71.value*7.50 
		+ document.bibershop.art74.value*4.00
		+ document.bibershop.art75.value*7.50;		
	
	netto = theValue;
	
	if(theValue<20 && theValue!=0) theValue +=5;
	
	document.bibershop.z_summe.value = runde(theValue,2);
	
	if (navigator.appName == "Microsoft Internet Explorer"){
document.getElementById("lieferkosten").style.display
= (( netto>20 || netto==0)?"none":"inline");
} else {
document.getElementById("lieferkosten").style.display
= (( netto>20 || netto==0)?"none":"table-row");
  }
	
}

//-->