var introindex = 1;
var introtimer = null;
var introtimerinterval = 4000;

function nextIntroIndex() {
  changeIntroIndex(introindex + 1);
}

function changeIntroIndex(i) {
  if(introtimer != null)
    window.clearTimeout(introtimer);
  i = i % 7;
  i = Math.max(1, i);
  introindex = i;  
  for(j = 1; j <= 6; j++) {
    if(i == j) $(".intro-" + j).addClass("selected");
    else       $(".intro-" + j).removeClass("selected");
  }

  $("div.intro, img.intro").animate({opacity: 0}, 200, "swing", function(){
    for(j = 1; j <= 6; j++) {
      $("div.intro-" + j + ", img.intro-" + j).css("display", introindex == j ? "block" : "none");
    }
    $("div.intro, img.intro").animate({opacity: 1}, 1, "swing", function(){
      if(introtimer != null)
        window.clearTimeout(introtimer);
      introtimer = window.setTimeout(nextIntroIndex, introtimerinterval);
    });    
  });
}

$(document).ready(function(){
  $(".intro-page a.intro-1").click(function(){changeIntroIndex(1);})
  $(".intro-page a.intro-2").click(function(){changeIntroIndex(2);})
  $(".intro-page a.intro-3").click(function(){changeIntroIndex(3);})
  $(".intro-page a.intro-4").click(function(){changeIntroIndex(4);})
  $(".intro-page a.intro-5").click(function(){changeIntroIndex(5);})
  $(".intro-page a.intro-6").click(function(){changeIntroIndex(6);})
  $(".intro-" + introindex).addClass("selected");  
  introtimer = window.setTimeout(nextIntroIndex, introtimerinterval);
  $(".button").hover(function(){
      $(this).addClass("hover");
      $('ul:first',this).css('visibility', 'visible');
  }, function(){
      $(this).removeClass("hover");
      $('ul:first',this).css('visibility', 'hidden');
  });
});