How to include the header/sidebar footer in this php file

Hello;

I’m using an advanced theme (markettheme) with a shopping cart included.
The problem is that the shopping cart is displayed inside a “thickbox” using javascript and CSS and I don’t like that way.

It’s easy to exclude the thickbox css, but the problem is that the shopping cart is displayed in a clean web page (no css of the theme no header, no sidebar, no footer).

So the question is: How to include the header/sidebar/footer in the shopping cart php file?

The shopping cart module is located in a specific folder inside the theme folder. And the way to call (link) this shopping cart from a simple button is:
<li><a href="<?php bloginfo('template_directory'); ?>/ajCart/cart.php?cart=true&height=220&width=600&CARTDIR=<?php bloginfo('template_directory'); ?>/ajCart/&PPEmail=<?php bloginfo('admin_email'); ?>" class="thickbox" title="Shopping Cart" >Shopping Cart</a></li>

I’m very newbie with php but I’ve been trying:
<?php get_header(); ?>
and
include("../header.php");
inside cart.php (the main php file of the module, and cart-top.php) unsuccesfully

It could be really nice if somebody can help me with this,
Thank you very much,
from Madrid,
Roy

Post Data:
If it could be helpfull, this is the code of cart.php:

<?php
session_start();

require("config.php");

//location of the cart directory
if($_GET["CARTDIR"]){
	$CARTDIR=$_GET["CARTDIR"];
	unset($_GET["CARTDIR"]);
}else{
	$CARTDIR="https://www.markettheme.com/demo/wp-content/themes/mk3/ajCart/";
}

$CARTURL = $CARTDIR."cart.php";

//Paypal Email
if($_GET["PPEmail"]){
	$PPEmail=$_GET["PPEmail"];
	unset($_GET["PPEmail"]);
}else{
	$PPEmail="[email protected]";
}

//TODO: Create Cart Object
$crtQuantity = array();
$crtAmount = array();
$crtShipping = array();
$crtShipping2 = array();
$crtHandling = array();
$crtHandlingCart = array();
$crtOptions = array();
$PPOptions = array();

//retrieve session Variables
if($_SESSION["Quantity"]){
	$crtName = $_SESSION["Name"];
	$crtQuantity = $_SESSION["Quantity"];
	$crtAmount = $_SESSION["Amount"];
	$crtShipping = $_SESSION["Shipping"];
	$crtShipping2 = $_SESSION["Shipping2"];
	$crtHandling = $_SESSION["Handling"];
	$crtHandlingCart = $_SESSION["HandlingCart"];
	$crtOptions = $_SESSION["Options"];
	$PPOptions = $_SESSION["PPOptions"];
}

//convert strings to integers
function str2int($string, $concat = true) {
    $length = strlen($string);
    for ($i = 0, $int = '', $concat_flag = true; $i < $length; $i++) {
        if (is_numeric($string[$i]) && $concat_flag) {
            $int .= $string[$i];
        } elseif(!$concat && $concat_flag && strlen($int) > 0) {
            $concat_flag = false;
        }
    }

    return (int) $int;
}

//Save Session Variables
function SaveSession($crtName,$crtAmount,$crtQuantity,$crtShipping,$crtShipping2,$crtHandling,$crtHandlingCart,$crtOptions,$PPOptions=' '){
	$_SESSION["Name"] = $crtName;
	$_SESSION["Quantity"] = $crtQuantity;
	$_SESSION["Amount"] = $crtAmount;
	$_SESSION["Shipping"] = $crtShipping;
	$_SESSION["Shipping2"] = $crtShipping2;
	$_SESSION["Handling"] = $crtHandling;
	$_SESSION["HandlingCart"] = $crtHandlingCart;
	$_SESSION["Options"] = $crtOptions;
	$_SESSION["PPOptions"] = $PPOptions;
}

//Monolithic display cart function
function ShowCart($crtName,$crtAmount,$crtQuantity,$crtShipping,$crtShipping2,$crtHandling,$crtHandlingCart,$crtOptions,$PPOptions){
	include("cart_top.php");

	global $CARTURL;

	$checkout = '';
	$i = 1;
		foreach( $crtAmount as $item =>$amount ){

			$Shipping = 0;

				if ($crtShipping[$item]){
					$Shipping = $crtShipping[$item];
						if ($crtQuantity[$item] > 1){
						$Shipping += $crtShipping2[$item] * ($crtQuantity[$item] - 1 );
						}
					$checkout .='<input type="hidden" name="shipping_'.$i.'" value="'.$Shipping.'" />';
				}	

			$Shipping = 'Shipping: €'.$Shipping;
			$content .= '<tr id="'.$item.'"><td>'.$crtName[$item].'</td><td>'.$crtOptions[$item].' '.$Shipping.'</td><td><input class="quantity" name="'.$item.'" type="text" value="'.$crtQuantity[$item].'" /></td><td><a href="'.$GLOBALS["CARTURL"].'?remove='.$item.'" class="crtRemove">Remove</a></td><td>€'.(float)($crtAmount[$item] * $crtQuantity[$item]).'</td></tr>';

				if ($crtHandling[$item]){
					$Handling = $crtHandling[$item];
						if($crtQuantity[$item] > 1){
							$Handling += $crtHandlingCart[$item] * ($crtQuantity[$item] - 1);
						}
					$checkout .='<input type="hidden" name="handling_'.$i.'" value="'.$Handling.'" />';
				}

			$checkout .='<input type="hidden" name="item_name_'.$i.'" value="'.$crtName[$item].'" />
		        <input type="hidden" name="amount_'.$i.'" value="'.$crtAmount[$item].'" />
		        <input type="hidden" name="quantity_'.$i.'" value="'.$crtQuantity[$item].'" />';
			  $tmp = explode("",$crtOptions[$item]);

			 $itr=0;
			  foreach ($tmp as $chk){
				if($chk!=""){
					list($opt,$val)=explode(":",$chk);
					$checkout.='<input type="hidden" name="on'.$itr.'_'.$i.'" value="'.$opt.'" /><input type="hidden" name="os'.$itr.'_'.$i.'" value="'.$val.'" />';
				}
			   ++$itr;
			  }

			//$checkout.=sprintf($PPOptions[$item],$i);
			++$i;
		}

	include("cart_bottom.php");
	echo $content;
}

if($_GET['cart']){
		ShowCart($crtName,$crtAmount,$crtQuantity,$crtShipping,$crtShipping2,$crtHandling,$crtHandlingCart,$crtOptions,$PPOptions);
}

if($_GET["remove"]){
	$item = $_GET["remove"];
	unset($crtName[$item]);
	unset($crtAmount[$item]);
	unset($crtQuantity[$item]);
	unset($crtShipping[$item]);
	unset($crtShipping2[$item]);
	unset($crtHandling[$item]);
	unset($crtHandlingCart[$item]);
	unset($crtOptions[$item]);
	SaveSession($crtName,$crtAmount,$crtQuantity,$crtShipping,$crtShipping2,$crtHandling,$crtHandlingCart,$crtOptions,$PPOptions);
}

if($_GET["update"]){
	foreach ($_GET as $item => $value ){

		if($crtQuantity[$item]){
			$crtQuantity[$item] = str2int($value);
		 }
	}
	SaveSession($crtName,$crtAmount,$crtQuantity,$crtShipping,$crtShipping2,$crtHandling,$crtHandlingCart,$crtOptions,$PPOptions);
	ShowCart($crtName,$crtAmount,$crtQuantity,$crtShipping,$crtShipping2,$crtHandling,$crtHandlingCart,$crtOptions,$PPOptions);
}

if($_GET["add"]){
	$item ="item".rand();//An Id can be used in lue of store with multiple items with the same name
	$name = $_GET["item_name"];
	$amt = (float)$_GET["amount"];
	$handling = (float)$_GET["handling"];
	$handling_cart = (float)$_GET["handling_cart"];
	$quan = str2int($_GET["quantity"]);
	$ppoptions = "";

	$options = "";
	$i = 0;

	if(strpos($_GET["shipping"],"/")){
		$ar = explode("/",$_GET["shipping"]);
		$ship = (float)$ar[0];
		$ship2= (float)$ar[1];
	}else{
		$ship = (float)$_GET["shipping"];
		$ship2= 0;
	}

	foreach ($_GET as $key => $value ){
		$val = substr($key,0,2);
			if($val=="on"){
				$opt = substr($key,2,1);
				$index = "os".$opt;
				$options.= $value.':'.$_GET[$index].'';
				/*Removed for testing
				$ppoptions.='<input type="hidden" name="'.$key.'_%1$d" value="'.$value.'" />';
				$ppoptions.='<input type="hidden" name="'.$index.'_%1$d" value="'.$_GET[$index].'" />';
				*/
				++$i;
			}

	}

		if($crtQuantity[$item]){// Is item in the array already?
			$crtQuantity[$item] += $quan;

				if($crtShipping[$item] < $ship){
					$crtShipping[$item] = $ship;
					$crtShipping2[$item] = $ship2;
					$crtHandling[$item] = $handling;
					$crtHandlingCart[$item] = $handling_cart;
				}
		}else{// A new item
			$crtName[$item] = $name;
			$crtAmount[$item] = $amt;
			$crtShipping[$item] = $ship;
			$crtShipping2[$item] = $ship2;
			$crtHandling[$item] = $handling;
			$crtHandlingCart[$item] = $handling_cart;
			$crtQuantity[$item] = $quan;
			$crtOptions[$item] = $options;
			$PPOptions[$item] = $ppoptions;
		}

	//Save the Session and Display the cart
	SaveSession($crtName,$crtAmount,$crtQuantity,$crtShipping,$crtShipping2,$crtHandling,$crtHandlingCart,$crtOptions,$PPOptions);
	ShowCart($crtName,$crtAmount,$crtQuantity,$crtShipping,$crtShipping2,$crtHandling,$crtHandlingCart,$crtOptions,$PPOptions);
}

?>