function clearvalues_s()
{
	document.getElementById('spot_ster_price1').value = "";
	document.getElementById('spot_ster_price2').value = "";
	document.getElementById('amount_silver').value = "";
	document.getElementById('calc_silver').value = "";
	document.getElementById('calc_total').value = "";
	document.getElementById('number_silver').innerHTML = "x (Spot Price x .815) ";
}

function calculatedefault_s()
{
	document.getElementById('amount_silver').value = "";
	if(validate_s())
	{
		var price = document.getElementById('spot_ster_price1').value + '.' + document.getElementById('spot_ster_price2').value;
		var s8 = (Math.round((price * .815 * 1)*100)/100).toFixed(2);
		document.getElementById('number_silver').innerHTML = "x " + s8;
	}

}

function calculate_s()
{
	if(validate_s())
	{
		i = 1;
		// 1 troy = 31.1034768 grams :: 0.032150746568627980522100346029483
		//document.getElementById('weight_gm_s').checked == true ? i=0.0321507465 : i=1;
		var price = document.getElementById('spot_ster_price1').value + '.' + document.getElementById('spot_ster_price2').value;
		var s8 = document.getElementById('calc_silver').value = document.getElementById('calc_total').value = (Math.round((price * i * .815 * document.getElementById('amount_silver').value)*100)/100).toFixed(2);
	}
}

function validate_s()
{
	retVal = true;
	errStr = "Invalid Data:\n\n";

	if(document.getElementById('spot_ster_price1').value == "") { errStr += "You must specify a Spot Price.\n"; retVal = false; }
	if(document.getElementById('spot_ster_price1').value != "" && isNaN(parseFloat(document.getElementById('spot_ster_price1').value))) { errStr += "Sterling Silver Spot Price value (dollars) must be numeric.\n"; retVal = false; }
	if(document.getElementById('spot_ster_price2').value != "" && isNaN(parseFloat(document.getElementById('spot_ster_price2').value))) { errStr += "Sterling Silver Spot Price value (cents) must be numeric.\n"; retVal = false; }
	if(document.getElementById('amount_silver').value != "" && isNaN(parseFloat(document.getElementById('amount_silver').value))) { errStr += "Sterling Silver value must be numeric.\n"; retVal = false; }
	
	
	if(!retVal) alert(errStr);
	return(retVal);
}