What I want to achieve is the following:
I want to have a tree-view list that will appear on the left side of the page, when an Item is expanded, it\'s items are loaded
Do you have any browser requirements? I have used the [CSS] Ninja example, along with selectivizr to support older versions of IE. Don't have an accessible example, apart from what is on the [CSS] Ninja site:
Pure CSS collapsible tree menu
And selectivizr:
selectivizr
The example is geared towards using it for a file navigation scenario, but you should be able to fairly easily modify it to remove the folders and file icons, should you want.