CSS how to position an element in a middle (half height / vertical 50%) of another element

Question

I\'m looking forward to build a tooltip which is positioned next to the element, but in a middle of it. It\'s easy to put it over and under and position it in the horizontal cen

Answer 1

using CSS & jQuery-

CSS

.div{
    top:50%
}

jQuery

var divheight = $(.div).height() / 2;
$(.div).attr('style','margin-top:-'+divheight+'px;');