添加如下几天语句页面变为空白，删除正常
echo "isset($tireqty)".isset($tireqty)."
";
echo "isset($nothere)".isset($nothere)."
";
echo "isset($tireqty)".empty($tireqty)."
";
echo "isset($nothere)".empty($nothere)."
";

下面列出完整代码

    
            
    
    
            
Bos's Auto Parts
            
Order Result

            Order processed at".date('H:i, jS F Y')."
";
                    echo " 
Your order is as follow:
";
                    echo $tireqty." tireqty
";
                    echo $oilqty." oilqty
";
                    echo $sparkqty." spark plugs 
";

                    $totalqty = 0;
                    $totalqty = $tireqty + $oilqty + $sparkqty;
                    echo "Items ordered: ".$totalqty."
";
                    $totalamount = 0.00;
                    $totalamount = $tireqty * TIREPRICE + 
                    $oilqty * OILPRICE + $sparkqty * SPARKPRICE;

                    echo "Subtotal: $".number_format($totalamount,2)."
";

                    $taxrate = 0.10;        //total sales tax is 10%
                    $totalamount = $totalamount * (1 + $taxrate);
                    echo "Total including tax: $".number_format($totalamount,2)."
"

// echo "isset($tireqty)".isset($tireqty)."
";
// echo "isset($nothere)".isset($nothere)."
";
// echo "isset($tireqty)".empty($tireqty)."
";
// echo "isset($nothere)".empty($nothere)."
";

            ?>