function harv_summe() {
var m2=1;

	for (var i=0;i<2;i++) {
		m2*=(parseFloat(document.getElementById("masze"+i).value));
	}
	document.getElementById("summe").value=Math.round(m2*document.getElementById("art").value*document.getElementById("multi").value*1.19*100)/100;
	document.getElementById("sum").firstChild.data=Math.round(m2*document.getElementById("art").value*document.getElementById("multi").value*1.19*100)/100;
}

function harv_summe_k() {
	var flaeche=0;
	flaeche=Math.PI * Math.pow(document.getElementById("durch").value/2,2);
	document.getElementById("summe_k").value=Math.round(flaeche*document.getElementById("art_k").value*document.getElementById("multi").value*1.19*100)/100;
	document.getElementById("sum_k").firstChild.data=Math.round(flaeche*document.getElementById("art_k").value*document.getElementById("multi").value*1.19*100)/100;
}


function eck_durch() {
	if (document.getElementById("rund").value==1) {
		document.getElementById("kreis").style.display="none";
	} else if (document.getElementById("rund").value==0) {
		document.getElementById("eck").style.display="none";		
	} else {
		document.getElementById("eck").style.display="none";		
		document.getElementById("kreis").style.display="none";
	}
}