function calc_ann(){
	var f = document.calcann;
	
	var v = f.currency.value;
	var n = parseFloat(f.period.value);
	
	var fsum = f.sum.value;
	
		switch(v)
	{
		case 'USD':
		case 'EUR':
			var procent = 13;
			if (fsum == 0)
			{
				fsum = 1;
			}

		break;
		
		case 'RUR':
			var procent = 18;
			if (fsum < 100000)
			{
				fsum = 100000;
			}
			
			if (fsum > 500000)
			{
				fsum = 500000;
			} 
		break;
	}
	
	var p = parseFloat(procent / 1200);	
	document.getElementById('sum').value = fsum;

	if (isNaN(n) || !n) {
		f.period.value=24;
		n=24;
		}

	var ezm = (p + p / (Math.pow(1 + p, n) - 1)) * fsum;
	var dohod = (ezm * 100) / 40;
	
	var html = '<table border="0" cellpadding="5" cellspacing="10">';
	
	html += '<tr><td>Процентная ставка</td><td>&ndash;</td><td><span id="res">'+procent+'%</span></td></tr>';
	html += '<tr><td>Сумма кредита</td><td>&ndash;</td><td><span id="res">'+fsum+' '+v+'</span></td></tr>';
	html += '<tr><td>Ежемесячный платеж</td><td>&ndash;</td><td><span id="res">'+nrm(ezm,1)+' '+v+'</span></td></tr>';
	html += '<tr><td>Минимальный доход</td><td>&ndash;</td><td><span id="res">'+nrm(dohod,1)+' '+v+'</span></td></tr>';	
	
	html += '</table>';
	
	var tbl=document.getElementById('tabl');
	tbl.innerHTML=html;
	}

function nrm(val, to) {
	var t = Math.round(val * to);
	var tt = t / to;
	return tt;
	}