// JavaScript Document<SCRIPT LANGUAGE="JavaScript">

function calculate(){

	ctype=1*document.form1.cType.value;

	y = 1*document.form1.period.value;
	l = document.form1.interest.value/100;
	loan = 1*(document.form1.loan.value-document.form1.self.value);

//	alert(loan);

	months = y*12;
	monthlyInterest = l/12;

	t = document.getElementById('tbl')
	t.style.display = "block";

//	alert(ctype);
//	alert(loan);

	while (t.getElementsByTagName( 'tbody' )[0].childNodes.length > 1) t.getElementsByTagName( 'tbody' )[0].removeChild(t.getElementsByTagName( 'tbody' )[0].childNodes[1])

	//for (var i =1; i < t.getElementsByTagName( 'tbody' )[0].childNodes.length; i++ ) t.getElementsByTagName( 'tbody' )[0].removeChild(t.getElementsByTagName( 'tbody' )[0].childNodes[i])

	if(ctype == 2) { //ravni vnoski po glavnicata
		for (j=1; j<=months; j++) {
			vnoska = loan/months + (months - j + 1)*loan*monthlyInterest/months;
			vnoska = vnoska.toFixed(2);
			
			
			var newRow = document.createElement('tr');
			var td1 = document.createElement('td');
			td1.innerHTML = j;
			var td2 = document.createElement('td');
			td2.innerHTML = vnoska;
			newRow.appendChild(td1)
			newRow.appendChild(td2)
			newRow = t.getElementsByTagName( 'tbody' )[0].appendChild(newRow)
			
			//newRow = t.insertRow();
			//td1 = newRow.insertCell()
			//td1.innerText = j;
			//td2 = newRow.insertCell()
			//td2.innerText = vnoska;
		} 
	} else {

		discontFactor = 0
		for (j=1; j<=months; j++) discontFactor += 1/Math.pow((1+monthlyInterest),j)
	
		monthlyPayment = loan / discontFactor;
		vnoska = monthlyPayment.toFixed(2)
		
		var newRow = document.createElement('tr');
		var td1 = document.createElement('td');
		td1.innerHTML = "Всеки";
		var td2 = document.createElement('td');
		td2.innerHTML = vnoska;
		newRow.appendChild(td1)
		newRow.appendChild(td2)
		newRow = t.getElementsByTagName( 'tbody' )[0].appendChild(newRow)

		//newRow = t.insertRow();
		//td1 = newRow.insertCell()
		//td1.innerText = "Всеки";
		//td2 = newRow.insertCell()
		//td2.innerText = vnoska;

	}
}