Moving from php4 to php5

I tried moving to php5, I am getting into lot of issues. This class gives error :

 Class DatabaseConnection 
 {                              // error here
     private $connection;
     private $result;   
     // 
     public function __construct()
     {
         $this->databaseName = $GLOBALS['configuration']['db'];
     }
     // other methods follow
 }

I have the following in the .htaccess file as well:

AddType x-mapp-php5 .php
php_value register_globals on

This is the error I get :

php5 error syntax error, unexpected T_STRING

Double check that PHP5 is working.