Hi there Magento developers!

I am trying to remove the Add New button from an Adminhtml grid in Magento 1.9.

I have found this post and this other one about doing that in Magento 2.0, but the same technique does not apply to Magento 1.9.

The error reported in Magento 1.9 is this:

exception 'Varien_Exception' with message 'Invalid method TBF_Cupom_Block_Adminhtml_Gerados_Index_Grid::_removeButton(Array
(
    [0] => add
)
)' in /var/www/html/lib/Varien/Object.php:653

In fact it makes sense because Grid's parent class is Mage_Adminhtml_Block_Widget_Grid and it does not have a _removeButton() method.

So, the question remains... How can I remove the Add New button from an Admin Grid Widget in Magento 1.9?

Thanks in advance!