calling variable from another classes function
<p>I have a class called ot_lev_discount </p>

<p>in that class I have a function:</p>

<pre><code>    &lt;?php
/*
&lt;&lt;&lt;&lt;&lt;&lt;&lt; ot_lev_discount.php
  $Id: ot_lev_discount.php,v 1.0 2002/04/08 01:13:43 hpdl Exp $
=======
  $Id: ot_lev_discount.php,v 1.3 2002/09/04 22:49:11 wilt Exp $
  $Id: ot_lev_discount.php,v 2.4 2006/02/28 12:10:01 maniac101 Exp $
modified to calc discount correctly when tax is included in discount
&gt;&gt;&gt;&gt;&gt;&gt;&gt; 2.4

  osCommerce, Open Source E-Commerce Solutions
  http://www.oscommerce.com

  Copyright (c) 2002 osCommerce

  Released under the GNU General Public License
*/

  class ot_lev_discount {
    var $title, $output;

    function ot_lev_discount() {
      $this-&gt;code = 'ot_lev_discount';
      $this-&gt;title = MODULE_LEV_DISCOUNT_TITLE;
      $this-&gt;description = MODULE_LEV_DISCOUNT_DESCRIPTION;
      $this-&gt;enabled = MODULE_LEV_DISCOUNT_STATUS;
      $this-&gt;sort_order = MODULE_LEV_DISCOUNT_SORT_ORDER;
      $this-&gt;include_shipping = MODULE_LEV_DISCOUNT_INC_SHIPPING;
      $this-&gt;include_tax = MODULE_LEV_DISCOUNT_INC_TAX;
      $this-&gt;calculate_tax = MODULE_LEV_DISCOUNT_CALC_TAX;
      $this-&gt;table = MODULE_LEV_DISCOUNT_TABLE;
//      $this-&gt;credit_class = true;
      $this-&gt;output = array();
    }

    function process() {
      global $order, $ot_subtotal, $currencies;
      $od_amount = $this-&gt;calculate_credit($this-&gt;get_order_total());
      if ($od_amount&gt;0) {
      $this-&gt;deduction = $od_amount;
      $this-&gt;output[] = array('title' =&gt; $this-&gt;title . ':',
                              'text' =&gt; '&lt;b&gt;' . $currencies-&gt;format($od_amount) . '&lt;/b&gt;',
                              'value' =&gt; $od_amount);
    $order-&gt;info['total'] = $order-&gt;info['total'] - $od_amount;
    if ($this-&gt;sort_order &lt; $ot_subtotal-&gt;sort_order) {
      $order-&gt;info['subtotal'] = $order-&gt;info['subtotal'] - $od_amount;
    }
}
    }


  function calculate_credit($amount) {
    global $order;
    $od_amount=0;
    $table_cost = split("[:,]" , MODULE_LEV_DISCOUNT_TABLE);
    for ($i = 0; $i &lt; count($table_cost); $i+=2) {
          if ($amount &gt;= $table_cost[$i]) {
            $od_pc = $table_cost[$i+1];
          }
        }
// Calculate tax reduction if necessary
    if($this-&gt;calculate_tax == 'true') {
// Calculate main tax reduction
      $tod_amount = round($order-&gt;info['tax']*10)/10*$od_pc/100;
      $order-&gt;info['tax'] = $order-&gt;info['tax'] - $tod_amount;
// Calculate tax group deductions
      reset($order-&gt;info['tax_groups']);
      while (list($key, $value) = each($order-&gt;info['tax_groups'])) {
        $god_amount = round($value*10)/10*$od_pc/100;
        $order-&gt;info['tax_groups'][$key] = $order-&gt;info['tax_groups'][$key] - $god_amount;
      }  
    }


   $od_amount = $od_pc;
   // if you want to use %age instead of flat amount:  $od_amount = round($amount*10)/10*$od_pc/100;


//    $od_amount = $od_amount + $tod_amount;
// maniac101 above line was adding tax back into discount incorrectly for me
    return $od_amount;
  }


  function get_order_total() {
    global  $order, $cart;
    $order_total = $order-&gt;info['total'];
// Check if gift voucher is in cart and adjust total
    $products = $cart-&gt;get_products();
    for ($i=0; $i&lt;sizeof($products); $i++) {
      $t_prid = tep_get_prid($products[$i]['id']);
      $gv_query = tep_db_query("select products_price, products_tax_class_id, products_model from " . TABLE_PRODUCTS . " where products_id = '" . $t_prid . "'");
      $gv_result = tep_db_fetch_array($gv_query);
      if (ereg('^GIFT', addslashes($gv_result['products_model']))) { 
        $qty = $cart-&gt;get_quantity($t_prid);
        $products_tax = tep_get_tax_rate($gv_result['products_tax_class_id']);
        if ($this-&gt;include_tax =='false') {
           $gv_amount = $gv_result['products_price'] * $qty;
        } else {
          $gv_amount = ($gv_result['products_price'] + tep_calculate_tax($gv_result['products_price'],$products_tax)) * $qty;
        }
        $order_total=$order_total - $gv_amount;
      }
    }
    if ($this-&gt;include_tax == 'false') $order_total=$order_total-$order-&gt;info['tax'];
    if ($this-&gt;include_shipping == 'false') $order_total=$order_total-$order-&gt;info['shipping_cost'];
    return $order_total;
  }   



    function check() {
      if (!isset($this-&gt;check)) {
        $check_query = tep_db_query("select configuration_value from " . TABLE_CONFIGURATION . " where configuration_key = 'MODULE_LEV_DISCOUNT_STATUS'");
        $this-&gt;check = tep_db_num_rows($check_query);
      }

      return $this-&gt;check;
    }

    function keys() {
      return array('MODULE_LEV_DISCOUNT_STATUS', 'MODULE_LEV_DISCOUNT_SORT_ORDER','MODULE_LEV_DISCOUNT_TABLE', 'MODULE_LEV_DISCOUNT_INC_SHIPPING', 'MODULE_LEV_DISCOUNT_INC_TAX','MODULE_LEV_DISCOUNT_CALC_TAX');
    }

    function install() {
      tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function, date_added) values ('Display Total', 'MODULE_LEV_DISCOUNT_STATUS', 'true', 'Do you want to enable the Order Discount?', '6', '1','tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
      tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, date_added) values ('Sort Order', 'MODULE_LEV_DISCOUNT_SORT_ORDER', '999', 'Sort order of display.', '6', '2', now())");
      tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function ,date_added) values ('Include Shipping', 'MODULE_LEV_DISCOUNT_INC_SHIPPING', 'true', 'Include Shipping in calculation', '6', '3', 'tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
      tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function ,date_added) values ('Include Tax', 'MODULE_LEV_DISCOUNT_INC_TAX', 'true', 'Include Tax in calculation.', '6', '4','tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
      tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function ,date_added) values ('Calculate Tax', 'MODULE_LEV_DISCOUNT_CALC_TAX', 'false', 'Re-calculate Tax on discounted amount.', '6', '5','tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
      tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, date_added) values ('Discount Percentage', 'MODULE_LEV_DISCOUNT_TABLE', '100:7.5,250:10,500:12.5,1000:15', 'Set the price breaks and discount percentages', '6', '6', now())");
    }

    function remove() {
      $keys = '';
      $keys_array = $this-&gt;keys();
      for ($i=0; $i&lt;sizeof($keys_array); $i++) {
        $keys .= "'" . $keys_array[$i] . "',";
      }
      $keys = substr($keys, 0, -1);

      tep_db_query("delete from " . TABLE_CONFIGURATION . " where configuration_key in (" . $keys . ")");
    }

  }
?&gt;
</code></pre>

<p>I want to echo the $od_amount variable from a different php file so I did the following to no avail:</p>

<pre><code>require(DIR_WS_MODULES . 'order_total/ot_lev_discount.php');
$ot_lev_discount = new ot_lev_discount();

echo $ot_lev_discount-&gt;od_amount;
</code></pre>

<p>I seem to be able to call the classes global variables in this way but not the ones in the classes function. </p>
