public static function getInstance()
 {
     if (self::$objInstance == null) {
         self::$objInstance = new AnoSelectComponente();
     }
     return self::$objInstance;
 }
        <ul>
            <li><a href="#tabs-1">Balancete Financeiro</a></li>            
        </ul>
        <div id="tabs-1">
            <div style="margin-bottom: 20px;">                
                <form>  
                    <fieldset class="coluna">
                        <label>Mês</label>
                        <?php 
echo MesSelectComponente::getInstance()->gerar("selMes", "BAL_Mes", date("m"));
?>
                    </fieldset>
                    <fieldset class="coluna">
                        <label>Ano</label>
                        <?php 
echo AnoSelectComponente::getInstance()->gerar("selAno", "BAL_Ano", date("Y"));
?>
                    </fieldset>
                    <fieldset class="coluna">
                        <input type="button" value="Gerar" onclick="gerar();" class="botao"/>
                    </fieldset>
                </form>
            </div>
            <?php 
// exportacao de conteúdo
include "../../sistema/gerencial/inc/export.inc.php";
?>
            <div id="relatorio"></div>
        </div>             
    </div>    
    <script type="text/javascript">