Magento 1.9如何将分页参数p更改为页面

Magento 1.9 how to change pagination parameter p to page. On pagination in url p is seen

lt/katalogas/autobuso-kebulas/autobuso-duru-sistema.html?p=2

I need to show like this

lt/katalogas/autobuso-kebulas/autobuso-duru-sistema.html?page=2

I googled and I have change the protected parameter to page in Mage_Page_Block_Html_Pager core but it didnt worked

protected $_pageVarName = 'page';