jquery rollovers and active states

I apologise for any stupid questions/coding, I'm very new to jquery!

I'm trying to create a menu for a one-page site that has rollovers and an active state. HTML:

<ul id="menu">
<li><a class="rollover" href="#"><img class="folio" src="images/folio3.png" /&g开发者_StackOverflow社区t;</a></li>
<li><a class="rollover" href="#"><img class="services" src="images/services3.png" /></a></li>
<li><a class="rollover" href="#"><img class="about" src="images/about3.png" /></a></li>
<li><a class="rollover" href="#"><img class="contact" src="images/contact3.png" /></a></li>
</ul>

jquery:

$(document).ready(function(){   
$("a.rollover").fadeTo(1,0.5);
$("a.rollover").hover(
        function() {$(this).fadeTo("fast",1);},
        function() {$(this).fadeTo("fast",0.5);});
$("a.rollover").click(function(){
if($(".active").length) {
    if($(this).hasClass("active")) {
    $(this).removeClass("active");
    $(this).fadeTo("fast",0.5);
    } else {
    $(".active").fadeTo("fast",0.5);
    $(".active").removeClass("active");
    $(this).addClass("active"); 
    $(this).fadeTo("fast",1);
    }
} else {    
    $(this).addClass("active");
    $(this).fadeTo("fast",1);
    }});
});

So there are two problems here:

1. Even though the active class is added and in Chrome's developer tools I can see that the opacity on an active class is "1", it doesn't seem to work in the browser, ie. the opacity still appears in the browser to be "0.5".

2. If $(this) is active, even after clicking $(this) thus removing the active class, the opacity remains at "1". If I click $(this) several times, eventually the opacity changes back to "0.5".

I'd really appreciate the help. I've been struggling with this for oh... 3 days now heh :-/

Many thanks in advance...

I think this should do what you are trying to do

$(document).ready(function(){   
    $("a.rollover").fadeTo(1,0.5);
    $("a.rollover").hover(function(){
        $(this).fadeTo("fast",1);
    },function(){
        if(!$(this).hasClass('active'))
        {
            $(this).fadeTo("fast",0.5);
        }
    });
    $("a.rollover").click(function(){
        if($('.active').length > 0)
        {                
            if($(this).hasClass('active'))
            {
                $(this).removeClass("active");
                $(this).fadeTo("fast",0.5);
            }
            else
            {
                $(".active").fadeTo("fast",0.5);
                $(".active").removeClass("active");
                $(this).addClass("active");
                $(this).fadeTo("fast",1);
            }
        }
        else
        {
            $(this).addClass("active");
            $(this).fadeTo("fast",1);
        }
        return false;
    });
});

Try this, crunched down a bit

$(function(){   
  $("a.rollover").fadeTo(1,0.5);
  $("a.rollover").hover(
    function() {$(this).stop().fadeIn("fast");},
    function() {$(this).stop().fadeTo("fast",0.5);}
  ).click(function(){
    var ia = $(this).hasClass("active"); //Was it active before?
    $(".active").fadeTo("fast",0.5).removeClass("active"); //Remove actives
    $(this).toggleClass("active", !ia); //Switch active to reverse of previous
    $(".active").stop().fadeIn("fast");//Fade in anything active (this if it is)
  }});
});

Try this, I think it should work:

$(function() {
    $("a.rollover img").fadeTo(1, 0.5);
    $(".active").fadeTo(0.5, 1);

    $("a.rollover img").hover(
        function() {
            if ( ! $(this).hasClass("active")) {
                $(this).stop().fadeTo("fast", 1);
            }
        },
        function() {
            if ( ! $(this).hasClass("active")) {
                $(this).stop().fadeTo("fast", 0.5);
            }
        }
    ).click(function() {
        var ia = $(this).hasClass("active"); //Was it active before?
        $(".active").fadeTo("fast", 0.5).removeClass("active"); //Remove actives
        $(this).toggleClass("active", !ia); //Switch active to reverse of previous
        $(".active").stop().fadeTo("fast", 1); //Fade in anything active (this if it is)
    });
});