function berechnefeld(Eingabe)
{
	if (Eingabe.value != null && Eingabe.value.length != 0) {
	Eingabe.value = eval(Eingabe.value);
	}
}

function berechneform(form)
{
	form.tlaenge.value=(1.0*form.laenge.value+2.0*form.tiefe.value+2.0*form.rand.value);
	form.tbreite.value=(1.0*form.breite.value+2.0*form.tiefe.value+2.0*form.rand.value);

    form.tlaenge.value=Math.ceil(form.tlaenge.value * 100.)/100. ;
    form.tbreite.value=Math.ceil(form.tbreite.value * 100.)/100. ;

    form.tgflaeche.value=(Math.ceil((form.tlaenge.value*form.tbreite.value)*100)/100);

}

function berechneformgflaeche(form)
{
     form.ergebnis.value = (Math.ceil((form.preis.value * form.tgflaeche.value)*100)/100);
}

function loescheform(form)
{
     form.laenge.value = "";
	 form.breite.value = "";
	 form.tiefe.value = "";
     form.rand.value = "";
	 form.tbreite.value ="";
}