How do i get this bar on top of a website?

Here is an example of a website: http://stackoverflow.com/
If you are a new vistior it displays a bar across the top that says " First time here? Check out the FAQ! "

How do i get something like that? I want it so it only shows up for people that visit the website for the first time.

 

I don't see any such bar, but there is a bar that tells me I suck for not have Javajunk enabled.

So my guess is, it's a Javajunk bar.

There's no way for them to truly know if you've ever been there, but they can try real hard by giving your browser a cookie that never expires. So long as their server recognises that cookie, the server can see that you're a returning person and can just not show that bar. No cookie? You must be new, and so get the bar.

However browsers like mine will dump all cookies after 7 days, or even every time I close my browser if I set it so.

Cookie-setting is usually done with Javascript as well. Possibly also why I do not see the New User? bar.

 

Yes, it is JavaScript

This code calls it on the homepage:

    <script type="text/javascript">
        $(function() { notify.showFirstTime(); });
    </script>

Code (markup):

 

is this javascript used on blogger blogs? if yes please tell me how to do so.

 

It is done with Javascript function

 

I think you have To get Some Scripts From HTML QUICK TIPS