Calculate height (or width etc.) of a hidden element

gistfile1.js

/**
 * Based on the following discussion:
 * http://stackoverflow.com/questions/2345784/jquery-get-height-of-hidden-element-in-jquery
 * @param jQuery $elem jQuery object
 */
function getHeightOfHiddenElem($elem) {
    $clone = $elem.clone();
    $clone.css({'position':'absolute','visibility':'hidden','display':'block'});
    $('body').append($clone)
    var height = $clone.height();
    $clone.remove();
    return height;
}