function calculate() 
{	var amount = document.getElementById('amount').value ;
	var from = document.getElementById('from')[document.getElementById('from').selectedIndex].value ;
	var to = document.getElementById('from')[document.getElementById('to').selectedIndex].value ;
		
	if ( ed_isEmpty(amount) )
	{ 	document.getElementById('result').value = 0;
		return false;
	}
	
	var rate = parseFloat(amount)*(parseFloat(from)/parseFloat(to));
	//alert(rate);
	//var result = document.getElementById('result').value;
	//if (result.indexOf('.') == -1) document.getElementById('result').value = rate;
	//else
	if (isNaN(rate)) 
	{	document.getElementById('result').value = 0 ;	}
	else
	{	document.getElementById('result').value = rate.toFixed(3);	}
}

function CheckKeyShift()
{	if (window.event.shiftKey || window.event.ctrlKey || window.event.altKey) event.keyCode = false;
}
	
function CheckNumber()
{	if (event.keyCode >=37 && event.keyCode <=40 || event.keyCode >= 48 && event.keyCode <=57 || event.keyCode >= 96 && event.keyCode <=105 || event.keyCode == 190 || event.keyCode == 110 || event.keyCode == 8 || event.keyCode == 46 || event.keyCode == 9) event.returnValue = true;
	else event.returnValue = false;
}

function ed_isEmpty(s)
{	return(s==null||s.length==0);	}