/**
	 * 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";
	                }
	            }
	        }
	    });
	};