function A()  {
  var Gewicht =  document.Formular.Gewicht.value;
  var Groesse = document.Formular.size.value;
  var Menge = document.Formular.Menge.value;
  var AlcGetr = document.Formular.AlcGetr.value;
  var AlcBl = document.Formular.AlcBl.value;
  var Alter = document.Formular.Alter.value;


if (document.Formular.Calc[0].checked == true) {
     var iGKW = GKW2(Menge, AlcGetr, AlcBl);
     if (document.Formular.geschlecht[0].checked  == true) {
	var Gewicht = (iGKW - 2.447 + (0.09516 * Alter) - (0.1074 * Groesse)) / 0.3362;
     } else {
	var Gewicht = (iGKW - 0.203 + (0.07 * Alter) - (0.1069 * Groesse)) / 0.2466;
     };
     window.document.Formular.Gewicht.value = Gewicht;
};
if (document.Formular.Calc[1].checked == true) {
     var iGKW = GKW2(Menge, AlcGetr, AlcBl);
     if (document.Formular.geschlecht[0].checked  == true) {
	var Groesse = (iGKW - 2.447 + (0.09516 * Alter) - (0.3362 * Gewicht)) / 0.1074;
     } else {
	var Groesse = (iGKW - 0.203 + (0.07 * Alter) - (0.2466 * Gewicht)) / 0.1069;
     };
     window.document.Formular.size.value = Groesse;
};
if (document.Formular.Calc[2].checked == true) {
     var iGKW = GKW(Gewicht, Groesse, Alter);
     var AlcGew = (AlcBl * iGKW) / 0.8;
     var Menge = (AlcGew * 1000) / (8 * AlcGetr);
     window.document.Formular.Menge.value = Menge;
};
if (document.Formular.Calc[3].checked == true) {
     var iGKW = GKW(Gewicht, Groesse, Alter);
     var AlcGew = (AlcBl * iGKW) / 0.8; 
     AlcGetr = AlcGew / ((Menge/1000) * 8);
     window.document.Formular.AlcGetr.value = AlcGetr;
};
if (document.Formular.Calc[4].checked == true) {
     var iGKW = GKW(Gewicht, Groesse, Alter);
     var AlcGew = (Menge/1000) * AlcGetr * 8;
     AlcBl = (0.8 * AlcGew) / iGKW;
     window.document.Formular.AlcBl.value = AlcBl;
};
};


function GKW(Gewicht, Groesse, Alter){
if (document.Formular.geschlecht[0].checked  == true) {
  iGKW = (2.447 - (0.09516 * Alter)) + (0.1074 * Groesse) + (0.3362 * Gewicht);
} else {
  iGKW = 0.203 - (0.07 * Alter) + (0.1069 * Groesse) + (0.2466 * Gewicht);
};
return iGKW;
};


function GKW2(Menge, AlcGetr, AlcBl) {
  var AlcGew = AlcGetr * (Menge/1000) * 8;
  var iGKW = (0.8 * AlcGew) / AlcBl;
  return iGKW;
};