Bien, he estado buscando por el foro y mas o menos me queda claro, pero tengo una prefabricada con estas variables y me cuesta saber que variable precisa de una u otra superglobal ($_get, $_post, etc...)
 
Pego codigo por si alguien tiene alguna sugerencia. Se agradece.
 
 
 
 
<table cellpadding=5 cellspacing=5  border="0" class="contenido">
 
 
 
<?php
 
 
 
$arr_item=explode("|",$myshop);
 
if (!empty($additem)){
      $item_id=$additem;
      $item_jm=1;
      if (!strstr($myshop,"$item_id:")){
         $apartament_item="|".$item_id.":".$item_jm;
         $myshop.=$apartament_item;
 
      }
}
 
 
if (!empty($edit_jml)){
   $item_id=$item_id;
   $item_jm=$edit_jml;
   for ($co=1; $co<count($arr_item); $co++){
      if (strstr($arr_item[$co],"$item_id:")){
         $olditem = "|".$arr_item[$co];
         $newitem = "|".$item_id.":".$item_jm;
         $apartament_item=str_replace($olditem,$newitem,$my  shop);
         $myshop=$apartament_item;
 
      }
   }
}
 
if (!empty($del_item)){
   $item_id=$del_item;
   for ($co=1; $co<count($arr_item); $co++){
      if (strstr($arr_item[$co],"$item_id:")){
         $olditem = "|".$arr_item[$co];
         $newitem = "";
         $apartament_item=str_replace($olditem,$newitem,$my  shop);
         $myshop=$apartament_item;
 
      }
   }
}
 
 
 
 
 
 
$arr_item=explode("|",$myshop);
 
 
$total=0;
$subtotal=0;
   if (!empty($myshop)){
      echo "<table border=0 cellspacing=1 cellpadding=4  class=contenido width=100%>";
 
       echo "<tr><td colspan=5><br />Aquesta es la seva reserva. Si us plau, indiquin's els numero de nits i procedeixi a establir el periode.<br /><br /></td></tr>";
 
      echo "<tr><td class=peti><b>Imatge</td><td class=peti><b>Apartament</td><td class=peti><b>Preu</td><td class=peti><b>Càlcul Preu/Nit</td><td class=peti><b>Subtotal(".$defcurr.")</td></tr>";
      for ($co=1; $co<count($arr_item); $co++){
         $item_picture="";
         $item_title="";
         $item_description="";
         $item_price="";
         $ro_shop=explode(":",$arr_item[$co]);
         $rs_item=@mysql_query("select * from apartament_item where id='$ro_shop[0]'");
         $ada_item=@mysql_num_rows($rs_item);
         if ($ada_item>0){
            $item_picture=@mysql_result($rs_item,0,"picture");
            $item_title=@mysql_result($rs_item,0,"title");
            $item_description=@mysql_result($rs_item,0,"descri  ption");
            $item_curr=@mysql_result($rs_item,0,"curr");
            $item_price=@mysql_result($rs_item,0,"price");
            $item_disc=@mysql_result($rs_item,0,"discount");
         }
         echo "<tr>";
         echo "<td align=center valign=top width=1>";
         if ( (!empty($item_picture)) and (file_exists($item_picture)) ){
 
            echo "sin imagen";
            } else{
            $imgarr=@getimagesize($item_picture);
            $winwidth=$imgarr[0]+40;
            $winheight=$imgarr[1]+120;
 
            echo "<img src='imatges_ap/".$item_picture."' alt=imagen border=0 width=100 /> ";
 
 
 
         }
         echo "</td>";
         echo "<td><span class=titulardetalle>".$item_title."</span><br />";
         echo "<br><span class=desc>".$item_description."</span>";
         echo "<br /><br /><a href='detall.php?detail_id=".$ro_shop[0]."' class=black><img src=img/boton_detalle.png border=0 alt=ver detalle longdesc=ver detalle /></a> <a href='".$PHP_SELF."?del_item=".$ro_shop[0]."' class=black><img src=img/cancelar.png border=0 alt=cancelar longdesc=cancelar /></a>";
         echo "</td>";
         echo "<td align=right valign=top nowrap>";
         if (!empty($item_disc)){
            echo "<font color=#FF0000>".$item_curr." <strike>".number_format($item_price, 2)."</strike></font>";
            echo "<br><font color=#008080>Desc: ".$item_disc."%</font>";
            $item_price=$item_price - ($item_price*($item_disc/100));
            echo "<br>".$item_curr." ".number_format($item_price, 2);
         } else {
            echo  "<span class=preu>".number_format($item_price, 2)." ".$item_curr."</span>";
         }
 
if ($defcurr<>$item_curr){
   $curr_from=@mysql_result(@mysql_query("select curr_value from shop_curr where curr_name='$item_curr'"),0,0);
   $curr_to=@mysql_result(@mysql_query("select curr_value from shop_curr where curr_name='$defcurr'"),0,0);
   if ( (!empty($curr_from)) and (!empty($curr_to)) ){
      $item_price=($item_price*$curr_to)/$curr_from;
      echo "<br>(".$defcurr." ". number_format($item_price,2).")";
   } else {
 
   }
}
 
 
 
 
 
 
 
 
         echo "</td>";
         echo "<td align=right valign=top><select onChange=\"window.location = this.options[this.selectedIndex].value\" ";
         echo ">";
         for ($c=1;$c<=10;$c++){
            echo "<option";
            if ($c==$ro_shop[1]){ echo " selected"; }
            echo " value='afegir_reserva.php?item_id=".$ro_shop[0]."&edit_jml=".$c."'>".$c."</option>";
         }
         echo "</select>";
 
 
 
 
 
 
 
         echo "</td>";
         $subtotal=$ro_shop[1]*$item_price;
         echo "<td align=right valign=top class=preu>".number_format($subtotal, 2)."</td>";
         echo "</tr>";
         $total=$total+$subtotal;
      }
      echo "<tr><td class=peti colspan=4 align=right><b>T O T A L</td>";
      echo "<td class=tota align=right><b>".number_format($total, 2)."</td></tr>";
      echo "</table>";
      echo "<div align=right><br>";
      echo "<a href='apartaments.php' ><img src=img/tornar.png border=0 /></a>  ";
      echo "<input type='image' src=img/periodo.png name='btorder' value='Triar el periode' class=but onclick=window.location='ordenar.php'>   ";
      echo "<br /><br /></div>";
   } else {
      echo "<div align=center><h3><br>No tè cap reserva efectuada,<br><a href='apartaments.php' class=black>Visiteu els apartaments</a>...!</h3></div>";
   }
?> 
  
 
 
