function check() { 
	var loanamt = top.document.loan_form.amt.value;
	var paymnt = top.document.loan_form.pay.value;
	var rate = top.document.loan_form.rate.value;

	if(loanamt=="" || isNaN(parseFloat(loanamt)) || loanamt==0) { 
		alert("Моля, въведете сума на кредита.");
		top.document.loan_form.amt.value="";
		top.document.loan_form.amt.focus();
		return false; 
	} else if(paymnt=="" || isNaN(parseFloat(paymnt)) || paymnt==0) {
		alert("Моля, посочете колко месеца е периода на изплащане.");
		top.document.loan_form.pay.value="";
		top.document.loan_form.pay.focus();
		return false; 
	} else if(rate=="" || isNaN(parseFloat(rate)) || rate==0) {
		alert("Моля, въведете лихвен процент.");
		top.document.loan_form.rate.value="";
		top.document.loan_form.rate.focus();
		return false; 
	} else {
		show(); 
	}
}

function clearScreen() { 
	top.document.loan_form.amt.value="";
	top.document.loan_form.pay.value="";
	top.document.loan_form.rate.value="";
	top.document.getElementById("pmt").innerHTML="";
	top.document.getElementById("det").innerHTML="";
}

function fixVal(value,numberOfCharacters,numberOfDecimals,padCharacter) { 
	var i, stringObject, stringLength, numberToPad;          

	value=value*Math.pow(10,numberOfDecimals);              
	value=Math.round(value);                                

	stringObject=new String(value);                         
	stringLength=stringObject.length;                      
	while(stringLength<numberOfDecimals) {                 
		stringObject="0"+stringObject;                     
		stringLength=stringLength+1;                      
	}

	if(numberOfDecimals>0) {			          
		stringObject=stringObject.substring(0,stringLength-numberOfDecimals)+"."+
		stringObject.substring(stringLength-numberOfDecimals,stringLength);
	}

	if (stringObject.length<numberOfCharacters && numberOfCharacters>0) {
		numberToPad=numberOfCharacters-stringObject.length;      
		for (i=0; i<numberToPad; i=i+1) {
			stringObject=padCharacter+stringObject;
		}
	}

	return stringObject;                                      
}

function show() {
	var amount=parseFloat(top.document.loan_form.amt.value);
	var numpay=parseInt(top.document.loan_form.pay.value);
	var rate=parseFloat(top.document.loan_form.rate.value);
 
	rate=rate/100;
	var monthly=rate/12;
	var payment=((amount*monthly)/(1-Math.pow((1+monthly),-numpay)));
	var total=payment*numpay;
	var interest=total-amount;

	var output = "";
	var detail = "";

//	output += "<table align='center' style='width:90%;margin:10px'> \
//			<tr><td>Сума на кредита Ви:</td><td align='right'>$"+amount+"</td></tr><tr><td>Период (в месеци):</td> \
//			<td align='right'>"+numpay+"</td></tr><tr><td>Годишна лихва:</td><td align='right'>"+fixVal(rate,0,4,' ')+"</td></tr> \
//			<tr><td>Месечна лихва:</td><td align='right'>"+fixVal(monthly,0,5,' ')+"</td></tr><tr><td>Месечна вноска:</td> \
//			<td align='right'>$"+fixVal(payment,0,2,' ')+"</td></tr><tr><td>Сума с лихвите:</td><td align='right'>$"+fixVal(total,0,2,' ')+"</td></tr> \
//			<tr><td>Пълна лихва:</td><td align='right'>$"+fixVal(interest,0,2,' ')+"</td></tr></table>";

	output += "<table align='center' style='width:90%;margin:10px'> \
			<tr><td>Сума на кредита:</td><td align='right'>"+amount+" лв.</td></tr><tr><td>Период (в месеци):</td> \
			<td align='right'>"+numpay+" мес.</td></tr><tr><td>Лихвен процент:</td><td align='right'>"+rate*100+"%</td></tr> \
			<tr><td><!-- Месечна лихва:</td><td align='right'>"+fixVal(monthly,0,5,' ')+" --><hr /></td></tr><tr><td><b>Мес. вноска:</b></td> \
			<td align='right'>"+fixVal(payment,0,2,' ')+" лв.</td></tr><tr><td><b>Сума с лихвите:</b></td><td align='right'>"+fixVal(total,0,2,' ')+" лв.</td></tr> \
			<tr><td><!-- Пълна лихва:</td><td align='right'>$"+fixVal(interest,0,2,' ')+" --></td></tr></table>";

	detail += "<meta http-equiv='Content-Type' content='text/html; charset=windows-1251' /><table border='0' align='center' cellpadding='5' cellspacing='0' width='97%' style='font-family:arial;font-size:12px'> \
			<tr><td align='center' valign='bottom' bgcolor='white'><b>Период</b></td><td align='right' valign='bottom' bgcolor='white'><b>Мес.вноска</b></td> \
			<td align='right' valign='bottom' bgcolor='white'><b>Сума на лихвата</b></td><td align='right' valign='bottom' bgcolor='white'><b>О.К.</b></td> \
			<td align='right' valign='bottom' bgcolor='white'><b>Салдо</b></td></tr><tr><td align='center' bgcolor='white'>0</td> \
			<td align='center' bgcolor='white'>&nbsp;</td><td align='center' bgcolor='white'>&nbsp;</td><td align='center' bgcolor='white'>&nbsp;</td> \
			<td align='right' bgcolor='white'>"+fixVal(amount,0,2,' ')+"</td></tr>";

	newPrincipal=amount;

	var i = 1;
	while (i <= numpay) {
		newInterest=monthly*newPrincipal;
		reduction=payment-newInterest;
		newPrincipal=newPrincipal-reduction;
		
		detail += "<tr><td align='center'>"+i+"</td><td align='right' bgcolor='white'>"+fixVal(payment,0,2,' ')+"</td> \
				<td align='right' bgcolor='white'>"+fixVal(newInterest,0,2,' ')+"</td> \
				<td align='right' bgcolor='white'>"+fixVal(reduction,0,2,' ')+"</td> \
				<td align='right' bgcolor='white'>"+fixVal(newPrincipal,0,2,' ')+"</td></tr>";

		i++;
	}

	detail += "</table>";

	document.getElementById("pmt").innerHTML = output;
	document.getElementById("det").innerHTML = detail;
}