How to disable pop up's in Opera browser

                Even with the best blockers installed, some pop-up windows will still manage to pass through. A common technique, used by aggressive advertisers, is triggering pop-ups by user actions such as clicking on a text box or simply moving the mouse over a certain area. Opera offers an extreme, yet effective solution which is to block all pop-ups with no exceptions. 

To block these agressive pop up's in Opera Click on "Tools" option and then select "Quick preferences" tab 

Now select the option "Block all pop-ups". 

To allow a pop-up, you can simply click on the notification box that appears whenever a pop-up is blocked.and select the allow pop up option.