<!--
function check(field){
		var komma = 0;
		var numb1=field.value
		if (field.value.length==0||field.value==" "){field.value=0;}
		for (var i1 = 0;i1 < numb1.length;i1++){
			if(numb1.substring(i1,i1+1) == ","){
				komma+=1;
				if (komma>1){return false}}
			else
			if(numb1.substring(i1,i1+1) != "." && isNaN(numb1.substring(i1,i1+1))){
				if(numb1.substring(i1,i1+1)=="-"){
					if(i1!=0){return false}}
				else {return false;}
			}
		}
		return true;
	}

function format_feld(field,decimals){
		if (check(field)){
		start=0;				
		var sign="";
		var dot=0;
		var x=0;
		
		if (decimals==0){
		 field.value=Math.round(field.value); 
		}
		numb1=field.value+"";
		if (numb1.substring(0,1)=="-"){
			start=1;
			sign="-";
			numb1=numb1.substring(1,numb1.length);
		}
		///// Punkt als Komma interpretieren 
		for (var i1 = 0;i1 < numb1.length;i1++){
			if (dot>=1){
			x+=1;
			}
			if(numb1.substring(i1,i1+1) == "."){
				dot+=1
			}
		}
		if (dot==1 && numb1.indexOf(",")<=0 && x<3){
		numb1=repl_char(numb1,".",",")
		}
		numb1=remov_dot(numb1);
		numb1=repl_char(numb1,",",".");
		numb1=runde_x(numb1);
		numb1=repl_char(numb1,".",",");
		var komma=numb1.indexOf(",");
		num_right=numb1.substring(komma,numb1.length);
		num_left=numb1.substring(0,komma);
		num_middle="";
		while (num_left.length>3){
			num_middle="."+num_left.substring(num_left.length-3,num_left.length)+num_middle;
			num_left=num_left.substring(0,num_left.length-3);
		} /*Ende von while */
		if(decimals==1){
	    numb1=sign+num_left+num_middle+num_right;}
		else{
		  numb1=sign+num_left+num_middle;}
			field.value=numb1	
		}	
		else{
			alert ("Bitte nur ganze Zahlen eingeben!");
			field.value = "";
			field.focus();
		}
	}

function runde_x(wertrunden){
		var help_l = "";
		var help_r = "";
		var sign="";
		
		if (wertrunden < 0){
		sign="-";
		wertrunden=wertrunden*-1;
		}
		if (wertrunden < 1){help_l = "0";}
		if (wertrunden < 0.1){
			help_l = "0";
			help_r = "0";
		}
		wertrunden = Math.round(wertrunden*100);
		wertrunden = wertrunden + "";
		var laenge2 = wertrunden.length;
		var wertrunden_left = wertrunden.substring(0,laenge2-2);
		if(wertrunden_left.length>0){help_l=""}
		var wertrunden_right = wertrunden.substring(laenge2-2,laenge2);
		wertrunden = sign+wertrunden_left + help_l + "." + help_r + wertrunden_right;
		return wertrunden;
	}

function repl_char(lokal,character1, character2){
	///// Character 1 durch Character ersetzen
		lokal=lokal+"";
		var indx=lokal.indexOf(character1)
		while (indx >= 0){
			var lokal_left = lokal.substring(0,indx);
			var lokal_right = lokal.substring(indx+1,lokal.length);
			lokal = lokal_left + character2 + lokal_right;
			indx=lokal.indexOf(character1)
			}
		return lokal
	}

function remov_dot(lokal){
		lokal=lokal+"";
		for (var i1 = 0;i1 < lokal.length;i1++){
			if(lokal.substring(i1,i1+1) == "."){
			var dot=lokal.indexOf(".")
				while (dot >= 0){
				var lokal_left = lokal.substring(0,dot);
				var lokal_right = lokal.substring(dot+1,lokal.length);
				lokal = lokal_left + lokal_right;
				dot=lokal.indexOf(".")
				}
			}
		
		}
		return lokal
	}

function lese_value(field){
		var lokal=field.value;
		lokal=remov_dot(lokal);
		lokal=repl_char(lokal,",",".");
		return lokal
	}

function mietzins_input(field){
		lokal = lese_value(field);
		rechnewert(field.form);
		format_feld(field,1);
}

function rechnewert(form){

  var jahre=parseInt(form.zeitraum.options[form.zeitraum.selectedIndex].value);
  var miete=parseInt(lese_value(form.miete));
  var steigerung=parseInt(form.steigerung.options[form.steigerung.selectedIndex].value);
  var summe=0;
  
  for(i = 1; i <= jahre; i++){
   summe+=12*miete;
   miete=miete+(miete/100*steigerung);
  }
  
  form.summe.value = runde_x(summe);
  format_feld(form.summe);
}

//-->