PHP Class extension does not seem to work

And so, I had a class defined on config.php. BUt , I cannot get the class extend done in another file (calc.php).

So, this is the calc.php:

error_reporting(0);

    define('BASE_PATH','some_path');
    include_once(BASE_PATH.'\config\config.php');


class Calc extends Main
{

    var $conn;
    var $table;
    var $query;
    var $where;



     function connect_db($connect) 
    {   

        $connect = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD)
                       or die ("Got problem");
                   mysql_select_db(DB_DATABASE)
                       or die ("Error: Can't access database");
         $this->connect = $conn;

    }



     function calc()    
    {



           if(isset($_POST['num_a']))
              $num_a = $_POST['num_a'];

            if(isset($_POST['num_b']))
              $num_b = $_POST['num_b'];

            if(isset($_POST['num_c']))
              $num_c = $_POST['num_c'];

            if(isset($_POST['num_d']))
              $num_d = $_POST['num_d'];

            if(isset($_POST['num_e']))
              $num_e = $_POST['num_e'];

            if(isset($_POST['num_f']))
              $num_f = $_POST['num_f'];

            if(isset($_POST['num_g']))
              $num_g = $_POST['num_g'];

            if(isset($_POST['num_h']))
              $num_h = $_POST['num_h'];

            if(isset($_POST['num_i']))
              $num_i = $_POST['num_i'];

            if(isset($_POST['num_j']))
              $num_j = $_POST['num_j'];

             $total_deduct = $num_b + $num_c + $num_d + $num_e + $num_f + $num_g + $num_h + $num_i + $num_j;
             $total_nett = $num_a - $total_deduct;

                if($num_a < $total_deduct)
                   $num_a * -1;

                      if($this->connect == 1)
                        {                         
                          $query = "INSERT INTO tbl_current_deductions
                                    (num_a,num_b,num_c,num_d,num_e,num_f,num_g,num_h,num_i,num_j)
                                    VALUES";

                            if($query)  
                            {  
                                if(mysql_num_rows($query) == 1 )  
                                {  
                                    return true;  
                开发者_如何学编程                }  
                                else  
                                {  
                                    trigger_error("SQL", E_USER_ERROR);
                                    return false;  
                                }  
                            }           



                              echo "<meta http-equiv='refresh' content='3;url=http://localhost/some_path'>
                                          <table width='100%' border='0' cellspacing='0' cellpadding='1'>
                                            <tr>
                                              <td align ='center'>
                                                  <p style='font: 11pt Arial Rounded MT Bold; color:#999999;'>
                                                     Nett balance is ". $total_nett." <br/>
                                                     Total deduction is ". $total_deduct."
                                                  </p>
                                              </td>
                                            </tr>
                                          </table>";

                        }else{
                         exit;
                        }                       


    }  

  } 

It seems you did not instanciate any Calc object, nor that you called the calc() method on it.