Question: Can someone tell me, what the href with the "#" means?

```
<a id="logoutLink" href="#">Logout</a>

```

Answer: 
It means nothing... ;) Normally we use `#something` to create anchor to some element. If your URL ends with `...#comments` then your browser will automatiacly jump (scroll the page) to element with `id="comments"`.

`href="#"` is often used to create a link that leads to nowhere.
It means make this page an anchor and navigate to it - which is why you see '#' after your URL in the address line (which can have nasty side-effects). Its also why your page will scroll back up to the top if you click on the link (sidenote: you can avoid this by adding "return false;" at the end of your onclick handler)