Finds maximum zIndex of an element

jq.fn.maxZIndex.js

/**
 *  Finds maximum zIndex of an element
 */

;(function (global) {
    var $ = global.jQuery || global.Zepto;

    var maxZIndex = function maxZIndex(el,min) {
        var el   = this
        ,   zIdx = el.css('zIndex')
        ,   cpr  = zIdx === 'auto' ? 0 : zIdx
        ,   _cnt = 0
        ,   _lev = 0
        ,   $e   = $([0])
        ,   rec_cpr = function rec_cpr(v,e) {
                $e[0] = e;
                ++_cnt;
                if($e.css('position') == 'static') {
                    ++_lev;
                    $e.children().each(rec_cpr);
                    --_lev;
                }
                else {
                    v = parseInt($e.css('zIndex'));
                    if(!isNaN(v) && cpr <= v) {
                        ++v;
                        zIdx = cpr = v;
                    }
                }
            }
        ;
        if(min != NULL) {
            zIdx = cpr = Math.max(min, cpr);
        }
        el.siblings().each(rec_cpr);
        return zIdx
    };

    $.fn.maxZIndex = maxZIndex;

})(this);