private void actualizarTotal(){
        if(!reciboExiste){
            BigDecimal subtotal=new BigDecimal(0);        
            for(int i=0;i<jTable1.getModel().getRowCount();i++){
                if(!esExento(modelo.getValueAt(i,0).toString()))
                    subtotal=this.sumarBigDecimal(subtotal+"", modelo.getValueAt(i,4).toString());
            }
            int sitFrenteIva=Integer.parseInt(field_situacion_IVA.getText());
            BigDecimal total=new BigDecimal(0);        
            BigDecimal totalIva=new BigDecimal(0);
            totalIva=this.sumarBigDecimal(totalIva+"", field_iva_general.getText());
            totalIva=this.sumarBigDecimal(totalIva+"", field_tasa_diferencial.getText());
            totalIva=this.sumarBigDecimal(totalIva+"", field_tasa_reducida.getText());            
            field_total_iva.setText(totalIva+"");
            if(sitFrenteIva==1){  // si es RESPONSABLE INSCRIPTO
                total=this.sumarBigDecimal(total+"", convertirEnBigDecimal(field_exento.getText())+"");
                total=this.sumarBigDecimal(total+"", convertirEnBigDecimal(field_no_gravado.getText())+"");
                total=this.sumarBigDecimal(total+"", convertirEnBigDecimal(field_total_iva.getText())+"");            
                total=this.sumarBigDecimal(total+"", convertirEnBigDecimal(field_sobretasa.getText())+"");
                total=this.sumarBigDecimal(total+"", convertirEnBigDecimal(field_impuesto_interno.getText())+"");                        
                jTextField11.setText(total+"");
                jTextField10.setText(field_no_gravado.getText()+"");        
            }        
            else
            {
                total=this.sumarBigDecimal(subtotal+"", convertirEnBigDecimal(field_exento.getText())+"");
                jTextField11.setText(total+"");
                jTextField10.setText(field_no_gravado.getText()+"");
            }                
        }
        else  // en caso de que sea un recibo
        {
            BigDecimal subtotal=new BigDecimal(0);
            for(int i=0;i<jTable1.getModel().getRowCount();i++){
                subtotal=this.sumarBigDecimal(subtotal+"", jTable1.getModel().getValueAt(i,1).toString());
            }
            jTextField11.setText(subtotal+"");
        }
    }