function enlarge(el){
  var src = $('div#main .navigation .'+el).children().children().attr("src").replace("small", "big");
  $('div#main .navigation .'+el).children().children().attr("src",src);
  $('div#main .navigation .'+el).children().children().stop().animate({
    height: "100%",
    width: "100%"
  },200);
}

function smaller(el){
  $('div#main .navigation .'+el).children().children()
  $('div#main .navigation .'+el).children().children().stop().animate({
    height: "83%",
    width: "83%"
  },200, function() {  
      var src = $('div#main .navigation .'+el).children().children().attr("src").replace("big", "small");
      $('div#main .navigation .'+el).children().children().attr("src",src);
  });
}