function formatCurrency(num) 
{
	num = num.toString().replace(/\$|\,/g,'');
	if(isNaN(num))
	num = "0";
	sign = (num == (num = Math.abs(num)));
	num = Math.floor(num*100+0.50000000001);
	cents = num%100;
	num = Math.floor(num/100).toString();
	if(cents<10)
	cents = "0" + cents;
	for (var i = 0; i < Math.floor((num.length-(1+i))/3); i++)
	num = num.substring(0,num.length-(4*i+3))+','+
	num.substring(num.length-(4*i+3));
	return (((sign)?'':'-') + '$' + num + '.' + cents);
}


function updateCart()
{
	var book_price = 14.95; 
	if (isNaN(document.getElementById("qty").value) || isNaN(document.getElementById("donate").value) || isNaN(document.getElementById("loan").value) )
	{
		alert ("Invalid entry");
		return;
	}
	
	if (document.getElementById("donate").value >0 && document.getElementById("donate").value < 5)
	{
		alert ("Minimum donation $5");
		return;	
	}

	if (document.getElementById("loan").value >0 && document.getElementById("loan").value < 1000)
	{
		alert ("Minimum loan amount $1,000");
		return;	
	}	
	document.getElementById("qty").value = Math.round(document.getElementById("qty").value); 
	document.getElementById("booksale").value = formatCurrency(Math.round(document.getElementById("qty").value * book_price *100)/100);
	document.getElementById("donate").value = Math.round(document.getElementById("donate").value*100)/100; 
	document.getElementById("loan").value =  Math.round(document.getElementById("loan").value*100)/100;
	document.getElementById("amount").value = Math.round(document.getElementById("donate").value*100)/100 +  Math.round(document.getElementById("loan").value*100)/100 + Math.round(document.getElementById("qty").value * book_price *100)/100 ;
	document.getElementById("total").value = formatCurrency(document.getElementById("amount").value); 
}

function otherCountry()
{
	if(document.getElementById('isDomestic').value ==0) 
	{
		document.getElementById('country').style.visibility ='visible'; 
		document.getElementById('country').focus();
	} else {
		document.getElementById('country').style.visibility ='hidden';
	}
}

function validateOrder()
{
	if (document.getElementById("amount").value <= 0 )
	{
		alert("$0 Total Amount"); 
		return false; 
	}
/*	
	if (document.getElementById("email").value =="")
	{
		alert ("Please enter your email address"); 
		return false; 
	}
*/	
	return true;
}

function validateDetails()
{

	if (document.getElementById("email").value =="")
	{
		alert ("Please enter your email address"); 
		return false; 
	}
	if (document.getElementById("isDomestic").value =="0" && document.getElementById("country").value =="" ) 
	{
		alert ("Please enter country"); 
		return false; 	
	}
	return true;
}