If you don't want certain website to show or block certain websites then there are some methods that block the particular website. Depending upon the browser you use, the method of blocking the website varies. Here is the method to block particular website on Firefox browser.

Easiest method to block website is using the free extension of Firefox. The extension is called BlockSite. It is free and you will find it at

Visit this site and download the extension. It is very small file. Install it and when prompted for restart, click ok. The Firefox will restart remembering all your settings.

Next is click on the Tool menu of Firefox browser. From drop down menu select Add-Ons. Click on the BlockSite, a small pop up will appear. This contains three options.

1. Enable BlockSite
2. Enable warning messages
3. Enable link removal

Now, check the first option "Enable BlockSite" and also check the Blacklist. This is important since if you don't check the Blacklist then you will only surf those sites that you have listed on white list.

It is also possible to use password for certain sites. This is very helpful feature for those parents who don't want certain sites to be seen by their kids. For this you have to click "Enable authentication" and after checking this option, you have to enter the password.

Now to block certain websites permanently, click on the button marked "Add" and then enter the full url of the website you want to block and press OK.

When you press OK button, the blocked site will be shown on Location list.

After this close your browser and restart the Firefox. Try to surf the blocked website and you will see that it is not possible. The blocked website just doesn’t load. If you have enabled the option “Enable warning messages", then while browsing the blocked website, you will see a message that this site is blocked.