采于www.phpbuilder.com,稍作补充。代码如下。嘻嘻：）
basket.php:
<?php
include ("evert.inc");
?>
<PRE>
ID    Name    Price
1     Mouse   25.00 <A HREF="<?echo $PHP_SELF; ?>?act=add&id;=1&price;=25&basket;=Mouse">add</A>  <A HREF="<?echo $PHP_SELF; ?>?act=subtract&id;=1&price;=25&basket;=Mouse">subtract</A>
2     Key    100.00 <A HREF="<?echo $PHP_SELF; ?>?act=add&id;=2&price;=100&basket;=Key">add</A>  <A HREF="<?echo $PHP_SELF; ?>?act=subtract&id;=2&price;=100&basket;=Key">subtract</A>
3     Car   5000.00 <A HREF="<?echo $PHP_SELF; ?>?act=add&id;=3&price;=5000&basket;=Car">add</A>  <A HREF="<?echo $PHP_SELF; ?>?act=subtract&id;=3&price;=5000&basket;=Car">subtract</A>
4     Game    25.00 <A HREF="<?echo $PHP_SELF; ?>?act=add&id;=4&price;=25&basket;=Game">add</A>  <A HREF="<?echo $PHP_SELF; ?>?act=subtract&id;=4&price;=25&basket;=Game">subtract</A>
</PRE>
<a href="<?echo $PHP_SELF;?>?logout=1">Logout</a>


evert.inc:
<?php
session_start();
if($logout){
session_destroy();
unset($ses_basket_name);
unset($ses_basket_amount);
unset($ses_basket_price);
unset($ses_basket_id);
unset($ses_basket_items);
}
if ($basket!=""){
                if (session_is_registered("ses_basket_items")){
                $basket_position_counter=0;
                $double=0;

                if ($ses_basket_items>0){
                   foreach ($ses_basket_name as $basket_item){
                      if ($basket_item==$basket){
                         $double=1;
                         $basket_position=$basket_position_counter;

                      }
                      $basket_position_counter++;
                   }
                }
              if ($double==1){
                $oldamount=$ses_basket_amount[$basket_position];
                if($act=="add")
                    $ses_basket_amount[$basket_position]++;
                else{
                    $ses_basket_amount[$basket_position]--;
                    if($ses_basket_amount[$basket_position]<0)
                       $ses_basket_amount[$basket_position]=0;
                    }
                 $amount=$ses_basket_amount[$basket_position];
                 $oldprice=$ses_basket_price[$basket_position];
                 $newprice=$oldamount>0?($oldprice/$oldamount)*$amount:$price;
                 $ses_basket_price[$basket_position]=$newprice;
                 }
               else{
                   $ses_basket_name[]=$basket;
                   $ses_basket_amount[]=1;
                   $ses_basket_price[]=$price;
                   $ses_basket_id[]=$id;
                   $ses_basket_items++;
                   }
        }else{
                $ses_basket_items=1;
                $ses_basket_name[0]=$basket;
                $ses_basket_amount[0]=1;
                $ses_basket_price[0]=$price;
                $ses_basket_id[0]=$id;
                session_register("ses_basket_items");
                session_register("ses_basket_name");
                session_register("ses_basket_amount");
                session_register("ses_basket_price");
                session_register("ses_basket_id");
        }
}

if ($ses_basket_items>0){
   for ($basket_counter=0;$basket_counter<$ses_basket_items;$basket_counter++){
      $price=sprintf("%01.2f",$ses_basket_price[$basket_counter]);
      $amount=$ses_basket_amount[$basket_counter];
      $name=$ses_basket_name[$basket_counter];
      if($amount>0){
        echo "$amount $name $price";
        echo "<BR>\n";
      }
   }
} else {
        $ses_basket_items=0;
        unset($ses_basket_name);
        unset($ses_basket_amount);
        unset($ses_basket_price);
        unset($ses_basket_id);
}

?>