var advanced_mode = 0;

// komma durch punkt ersetzen
function punktkomma(s)
{
	var result = "";

	for(var i=0; i<s.length; i++) {
		t = s.charAt(i);
		if(t == ',') t = '.';
		result = result + t;
	}
	
	return result;
}

function berechne_zinseszins()
{
	var inputError = 0;
	var toomuch = 0;
	
	var eingezahlt = 0;
	var steuern = 0;
	
	document.getElementById("startkapital").value = punktkomma(document.getElementById("startkapital").value);
	document.getElementById("zinsen").value       = punktkomma(document.getElementById("zinsen").value);
	document.getElementById("laufzeit").value     = punktkomma(document.getElementById("laufzeit").value);
	document.getElementById("zuzahlung").value    = punktkomma(document.getElementById("zuzahlung").value);
	document.getElementById("steuern").value      = punktkomma(document.getElementById("steuern").value);

	var money = parseFloat(document.getElementById("startkapital").value);
	if(!isFinite(money) || isNaN(money) || money < 0) {
		inputError = 1;
	}
	
	var percent = parseFloat(document.getElementById("zinsen").value);
	if(!isFinite(percent) || isNaN(percent) || percent < 0) {
		inputError = 1;
	}
	
	var years = parseFloat(document.getElementById("laufzeit").value);
	if(!isFinite(years) || isNaN(years) || years < 0) {
		inputError = 1;
	}
	
	var throwin = 0;
	var a = document.getElementById("zuzahlung").value;
	if(a != "") {
		throwin = parseFloat(a);
		if(!isFinite(throwin) || isNaN(throwin) || throwin < 0) {
			inputError = 1;
		}
	} else {
		document.getElementById("zuzahlung").value = 0;
	}	
			
	var taxes = 0;
	a = document.getElementById("steuern").value;
	if(a != "") {
		taxes = parseFloat(a);
		if(!isFinite(taxes) || isNaN(taxes) || taxes < 0) {
			inputError = 1;
		}
	} else {
		document.getElementById("steuern").value = 0;
	}
		
	if(taxes > 100) {
		alert("taxen zu hoch");
		inputError = 1;
	}
	
	if(inputError == 0) {
	} else {
		alert("Bitte Startkapital, Jahreszinssatz und Laufzeit sinnvoll ausfuellen!");
		return;
	}
	
	var p = 1 + (percent / 100);
	var q = 1 - (taxes / 100);
	
	eingezahlt = money;
	
	//var factor = 0;
	/*
	if(throwin != 0) {

		
		var y = document.forms[0].wieoft;
		alert("bla = " + y.options[y.selectedIndex].value);
		
		
		alert(x);
		
		if(x == "Monat") factor = 12;
		if(x == "Quartal") factor = 4;
		if(x == "halbem Jahr") factor = 2;
		if(x == "Jahr") factor = 1;
		
		alert("Faktor = " + factor);
	} else {
		alert("komisch...");
	}*/
	
	for(i = 0; i < years; i++) {
		
		var old = money;
		money = money * p;
		var zinsen = money - old;
		tmp = zinsen;
		zinsen = zinsen * q;
		steuern = steuern + (tmp - zinsen);		
		money = old + zinsen + (throwin); //*factor);
		eingezahlt = eingezahlt + (throwin); //*factor);
	}
	
	var sm = String(money);
	
	if(sm.indexOf("e") == -1) {
		if(sm.indexOf(".") != -1) {
			sm = sm.substring(0,sm.indexOf(".")+3);
		}
	} else {
		to_much();
		return;	
	}
	
	document.getElementById("einzahlung").innerHTML = Math.round(eingezahlt*100)/100;
	document.getElementById("ertrag").innerHTML = Math.round((sm - eingezahlt)*100)/100;
	document.getElementById("steuer").innerHTML = Math.round(steuern*100)/100;
	document.getElementById("auszahlung").innerHTML = "<b>" + Math.round(sm*100)/100; + "</b>";
}

function to_much()
{
	alert("Summe zu hoch!");
}