/**
 * Takes all matched elements and centers them, absolutely,
 * within the context of their parent element. Great for
 * doing slideshows.
 *
 * @example $("div img").center();
 * @name center
 * @type jQuery
 * @cat Plugins/Center
 */
jQuery.fn.center = function(f) {
    return this.each(function(){
        var p = this.parentNode;
        if ( jQuery.css(p,"position") == 'static' )
            p.style.position = 'relative';

        var s = this.style;
        s.position = 'absolute';
        if(!f || f == "horizontal") {
            if(((parseInt(jQuery.css(p,"width")) - parseInt(jQuery.css(this,"width")))/2) > 0)
                s.left = ((parseInt(jQuery.css(p,"width")) - parseInt(jQuery.css(this,"width")))/2) + "px";
            else
                s.left = "0";
        }
        if(!f || f == "vertical") {
            if(((parseInt(jQuery.css(p,"height")) - parseInt(jQuery.css(this,"height")))/2) > 0)
            {
                s.top = ((parseInt(jQuery.css(p,"height")) - parseInt(jQuery.css(this,"height")))/2) + "px";
            } else {
                if(p.nodeName.toLowerCase() == "body") {

                if (window.innerHeight)
                    var clientHeight = window.innerHeight;
                   else if(document.body && document.body.offsetHeight)
                    var clientHeight = document.body.offsetHeight;

                    s.top = ((clientHeight - parseInt(jQuery.css(this,"height")))/2) + "px";
                } else {
                    s.top = "0";
                }
            }
        }
    });
};