Response.php

<?php
/*
 * Template Name: Responce
 */

//I want to retrive sessionid variable inside this template file. 

class wpsc_merchant_citrus_standard extends wpsc_merchant {
  var $name = '';
  var $paypal_ipn_values = array();

  function __construct( $purchase_id = null, $is_receiving = false ) {
  	$this->name = __( 'PayPal Payments Standard', 'wpsc' );
  	parent::__construct( $purchase_id, $is_receiving );
  }
  
  function get_session_id() {
    return $this->cart_data['session_id'];
  }
}

I tried above code but it still giving me blank values.