how to create vertical tab or image on focus of that a autohide docable window comes.

[gauravg]

hi all
like in visual studio 2008 ,there is some (vertical image or tab) on focus of that tab or image a docable window comes out and when we remove focus from that tab or image
docable window becomes in statae of autohide.
what is that along with the window, is it a image or tab on focus of that a docable window come and autohide functionality performs. how it is performs


thanks with regards:
gauravg