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 isPositiveInteger(number)
{
	if(number==null)
	{
		return false;
	}
    
    if (number.length==0)
    {
    	return false;
    }
    
    for (var i = 0; i < number.length; i++)
    {
            var ch = number.charAt(i);
            if (ch < "0" || ch > "9") 
            {
            	return false;
            }
      }
}

function updatePrice()
{
	var subtotal;
	var taxes;
	var total;
	
	if(isNaN($('quantity').value) || isPositiveInteger($('quantity').value) == false)
	{
		alert('You must provide a valid numeric quantity!');	
	}
	else
	{
		subtotal = $('price').value * $('quantity').value;
		taxes = (subtotal * $('tax_percentage').value) / 100;
		total = subtotal + taxes;
		
		$('subtotal').update(formatCurrency(subtotal));
		$('taxes').update(formatCurrency(taxes));
		$('display_total').update(formatCurrency(total) + ' CAD');
	}
}

function changePrice()
{
	var Type = $('type').value;
	if(Type == 'group')
	{
		$('price').value = $('group_price').value;
		$('group').style.display = 'block';
		$('group_multiplier').style.display = 'inline';
		$('singular').style.display = 'none';
	}
	else
	{
		$('price').value = document.getElementById('singular_price').value;
		$('group').style.display = 'none';
		$('group_multiplier').style.display = 'none';
		$('singular').style.display = 'block';
	}
}

function toggleOptions()
{
	if($('type').value == "Events")
	{
		$('event').enable();	
	}
	else
	{
		$('event').disable();
	}
}