function KORechner() {

  var kg = document.Form.KG.value;
  var gr = document.Form.GR.value;
  var g = 0;
  if (document.Form.G[0].checked) { g = 1;}

  kg = kg.replace(",",".");
  gr = gr.replace(",",".");

  if (istZahl(kg) == 1| istZahl(gr) == 1) {
    alert("Mit Zahlen rechnet es sich besser!");
  }
  else {
    if (kg == 0 | gr == 0 | kg == null | gr == null) {
      document.Form.KO.value = "---";
    }
    else {
      if (g == 1) {
        var ko = Math.pow(10,(Math.log(kg)/Math.LN10)*0.425+(Math.log(gr)/Math.LN10)*0.725+1.8564)/10000;
      }
      else {
        var ko = Math.sqrt((kg*gr)/3600);
      }
      document.Form.KO.value = runden(ko);
    }
  }
}

function runden(y) {
  return Math.round(y*10000)/10000;
}

function istZahl(z) {
  var erlaubt = "0123456789.";
  var error = 0;
  for (var i = 0;i<z.length;i++) {
    if (erlaubt.indexOf(z.charAt(i)) == -1) {
      error = 1;
    }
  }
  return error;	
}

function GFR_CG() {

  var kg = document.Form.KG.value;
  var a = document.Form.A.value;
  var g = 1;
  var s = document.Form.S.value;
  var auc = document.Form.AUC.value;
  if (document.Form.G[0].checked) { g = 0.85;}

  kg = kg.replace(",",".");
  a = a.replace(",",".");
  s = s.replace(",",".");
  auc = auc.replace(",",".");

  if (istZahl(kg) == 1 | istZahl(a) == 1 | istZahl(auc) == 1 | istZahl(s) == 1) {
    alert("Mit Zahlen rechnet es sich besser!");
  }
  else {
    if (kg == 0 | a == 0 | s == 0 | kg == null | a == null | s == null) {
      document.Form.GFR.value = "---";
      document.Form.GFR25.value = "---";
    }
    else {
      var gfr =g*((140-a)*kg)/(72*s);
      var gfr25 = gfr+25;
      document.Form.GFR.value = runden(gfr);
      document.Form.GFR25.value = runden(gfr25);
      if (auc == 0 | auc == null) {
        document.Form.Dosis.value = "---";
      }
      else {
        var dosis = auc*gfr25;
	if (dosis > 9999.99) { document.Form.Dosis.value = "---";}
        else { document.Form.Dosis.value = runden(dosis);}
      }
    }
  }
}

function GFR_CH() {

  var kg = document.Form.KG.value;
  var a = document.Form.A.value;
  var g = 0;
  var s = document.Form.S.value;
  var auc = document.Form.AUC.value;
  if (document.Form.G[0].checked) { g = 1;}

  kg = kg.replace(",",".");
  a = a.replace(",",".");
  s = s.replace(",",".");
  auc = auc.replace(",",".");

  if (istZahl(kg) == 1 | istZahl(a) == 1 | istZahl(auc) == 1 | istZahl(s) == 1) {
    alert("Mit Zahlen rechnet es sich besser!");
  }
  else {
    if (kg == 0 | a == 0 | s == 0 | kg == null | a == null | s == null) {
      document.Form.GFR.value = "---";
    }
    else {
      var gfr = 0.134*kg+(218*kg*(1-0.00457*a)*(1-0.314*g))/(s*88.4);
      document.Form.GFR.value = runden(gfr);
      if (auc == 0 | auc == null) {
        document.Form.Dosis.value = "---";
      }
      else {
        var dosis = auc*gfr;
	if (dosis > 9999.99) { document.Form.Dosis.value = "---";}
        else { document.Form.Dosis.value = runden(dosis);}
      }
    }
  }
}

function GFR_J() {

  var kg = document.Form.KG.value;
  var gr = document.Form.GR.value;
  var a = document.Form.A.value;
  var g = 1;
  var s = document.Form.S.value;
  var auc = document.Form.AUC.value;
  if (document.Form.G[0].checked) { g = 0.9;}

  kg = kg.replace(",",".");
  gr = gr.replace(",",".");
  a = a.replace(",",".");
  s = s.replace(",",".");
  auc = auc.replace(",",".");

  if (istZahl(kg) == 1 | istZahl(a) == 1 | istZahl(auc) == 1 | istZahl(s) == 1  | istZahl(gr) == 1) {
    alert("Mit Zahlen rechnet es sich besser!");
  }
  else {
    if (kg == 0 | a == 0 | s == 0 | gr == 0 | kg == null | a == null | s == null | gr == null) {
      document.Form.GFR.value = "---";
      document.Form.GFR25.value = "---";
    }
    else {
      var ko = Math.pow(10,(Math.log(kg)/Math.LN10)*0.425+(Math.log(gr)/Math.LN10)*0.725+1.8564)/10000;
      var gfr =((98-0.8*(a-20))/s)*(ko/1.73)*g;
      var gfr25 = gfr+25;
      document.Form.KO.value = runden(ko);
      document.Form.GFR.value = runden(gfr);
      document.Form.GFR25.value = runden(gfr25);
      if (auc == 0 | auc == null) {
        document.Form.Dosis.value = "---";
      }
      else {
        var dosis = auc*gfr25;
	if (dosis > 9999.99) { document.Form.Dosis.value = "---";}
        else { document.Form.Dosis.value = runden(dosis);}
      }
    }
  }
}