function validate_amount(){
	clearErrors();
	var guarantee_amount = document.getElementById("guarantee_amount");
	var guarantee_remaining = parseFloat(document.getElementById("guarantee_remaining").value);

	if (guarantee_amount.value == '') {
		addError(getInvestorErrorMessage('GUARANTEE_AMOUNT_BLANK'), guarantee_amount);
	}	
	else if (isNaN(Trim(guarantee_amount.value))) {
		addError(getInvestorErrorMessage('GUARANTEE_AMOUNT_VALID'), guarantee_amount);
	}
	else if (Trim(guarantee_amount.value) <= 0) {
		addError(getInvestorErrorMessage('GUARANTEE_AMOUNT_GREATER'), guarantee_amount);
	}
	else if (Trim(guarantee_amount.value) > guarantee_remaining) {
		addError(getInvestorErrorMessage('GUARANTEE_AMOUNT_GREATER_INVALID') + guarantee_remaining + ")", guarantee_amount);
	}
	else {
		if (guarantee_amount.value.indexOf('.') != -1) {
			var guarantee_amount_array = guarantee_amount.value.split('.')
			if (guarantee_amount_array[1].length > 2) {
				addError(getInvestorErrorMessage('GUARANTEE_AMOUNT_DECIMAL_PLACES'), guarantee_amount);
			}
		}		
	}
	
	if (ifError()) {
		showErrors();
		document.location.href = '#top';
	}
	else {
		document.add_to_cart_frm.submit();
	} 
}

function calculate_total(sub_total_value, credit_amount){
	var total = document.getElementById("total");
	var checkout_total = document.getElementById("checkout_total");
	var apply_credit = "yes"
	
	if (credit_amount != 0) {
	  var selection = document.checkout_frm.apply_credit;
		
	  for (i = 0; i < selection.length; i++) {
        if (selection[i].checked == true) {
		  apply_credit = selection[i].value;
		}
	  }
	}
	
	if (apply_credit == "yes") {
		if (credit_amount != 0) {
		  document.checkout_frm.apply_credit[0].checked = true;
		}
		if (credit_amount >= sub_total_value) {
			total.innerHTML = "$" + 0.00.toFixed(2)
   		    checkout_total.value = 0.00.toFixed(2)
		}
		else {		
			total.innerHTML = "$" + (sub_total_value - credit_amount).toFixed(2)
	  		checkout_total.value = (sub_total_value - credit_amount).toFixed(2)
		}
	}
	else {
		total.innerHTML = "$" + sub_total_value
		checkout_total.value = sub_total_value
	}
}

function update_total(guarantee_total,credit_amount,gift_code_amount){
	var donation_fund = 0;
	var donation_fund_value = document.getElementById("sc_donation_fund_txt").value;
	var sc_donation_fund = document.getElementById("sc_donation_fund");
	var checkout_sub_total = document.getElementById("checkout_sub_total");
	
	if ((!isNaN(donation_fund_value)) && (donation_fund_value >= 0) && (donation_fund_value != ""))
	{
		if (donation_fund_value.indexOf('.') != -1) {
			var donation_fund_value_array = donation_fund_value.split('.');
			if (donation_fund_value_array[1].length <= 2) {			
				donation_fund = parseFloat(donation_fund_value);
			}
		}
		else {
			donation_fund = parseFloat(donation_fund_value);
		}		
	}	
	sc_donation_fund.value = donation_fund;	
	
	if (credit_amount != 0) {
	  var sub_total = document.getElementById("sub_total");	
	}
	
	var sub_total_value = (guarantee_total + donation_fund + gift_code_amount).toFixed(2);
	
	if (credit_amount != 0) {
		sub_total.innerHTML = "$" + sub_total_value;
	}
	checkout_sub_total.value = sub_total_value;
	
	calculate_total(sub_total_value,credit_amount);
}

function checkout(){
	clearErrors();
	
	var donation_fund_value = document.getElementById("sc_donation_fund_txt").value;
	var sc_donation_fund = document.getElementById("sc_donation_fund_txt");
	
	if (isNaN(donation_fund_value) || (donation_fund_value < 0))
	{
		addError(getInvestorErrorMessage('DONATION_AMOUNT_INVALID'), sc_donation_fund);		
	}
	else if (donation_fund_value.indexOf('.') != -1) {
		var donation_fund_value_array = donation_fund_value.split('.');
		if (donation_fund_value_array[1].length > 2) {
			addError(getInvestorErrorMessage('DONATION_AMOUNT_DECIMAL_PLACES'), sc_donation_fund);
		}
	}	
	
	if (ifError()) {
		showErrors();
		document.location.href = '#top';
	}
	else {
		document.checkout_frm.submit();
	} 	
	
}