magento 1.9 - How to get Order Incremented id in Mage::registry in All Totals page -

i want incremented id or order id mage::registry doing not work.

 class my_module_block_order_totals extends mage_sales_block_order_totals {              protected function _inittotals() {             parent::_inittotals();             $order = new mage_sales_model_order();             $order1 = $this->getorder();             $order_id = mage::registry('order_id');             }     } 

my observer.php

public function myfunction(varien_event_observer $observer) {          $mydata=$observer->getevent()->getorder();         mage::register('order_id' , $mydata->getincrementid());         //mage::log(mage::registry('order_id'));  } 

if on success page can id -

$orderid = $this->getorderid(); 

on other pages can follows above code would't work on other pages.

$orderid = mage::getsingleton('checkout/session')->getlastrealorderid();