(function($){
    Contenedor = function(element){    
    element = $("#"+element);
    var init = function(){
        center();
        $(window).resize(function(){center()});
    };
    var center = function(){
        var b = $("body")[0];
        var win_width = $(document).width();
	var win_height = $(document).height();
        var top = 20;
        var left = 20;
        if (win_width > 980)
            left = parseInt((win_width - 940)/2);
        if (win_height > 640)
            top = parseInt((win_height - 600)/2);        
        element.css("top",top+"px");
        element.css("left",left+"px");        
    };
    init();    
};
})(jQuery);