Select first "li" in multiple unorganized lists with jQuery

Problem demo is here: http://www.studioimbrue.com

Currently, when the page loads, all the thumbnails are triggered to dim. I'm trying to make it so that each first thumb remains at full opacity (using :first of course) until another thumb is clicked. I can get it to do it for the first one, but it won't iterate to each <ul>. I tried using the each() function, but I couldn't get it to work. My JavaScript skills aren't that great so if you find a solution, just post the code and then explain (if you can).

Below is the current code I'm working with:

$(document).ready(function(){
    var activeOpacity   = 1.0,
    inactiveOpacity = 0.6,
    fadeTime = 100,
    clickedClass = "selected",
    thumbs = ".thumbscontainer ul li";

    $(thumbs).fadeTo(1, inactiveOpacity);

    $(thumbs).hover(
        function(){
            $(this).fadeTo(fadeTime, activeOpacity);
        },
        function(){
            // Only fade out if the user hasn't clicked the thumb
            if(!$(this).hasClass(clickedClass)) {
                $(this).fadeTo(fadeTime, i开发者_开发问答nactiveOpacity);
            }
        });
    $(thumbs).click(function() {
        // Remove selected class from any elements other than this
        var clicked, previous;
        clicked = $(this);
        if (!clicked.hasClass(clickedClass)) {
            previous = $(thumbs+'.'+clickedClass);
            previous.removeClass(clickedClass).fadeTo(fadeTime, inactiveOpacity);
            clicked.addClass(clickedClass).fadeTo(fadeTime, activeOpacity);
        }
    });
});

You need :nth-child() or :first-child:

$(".thumbscontainer li:nth-child(1)")

And actually, just change the line that reads $(thumbs).fadeTo(1, inactiveOpacity); to this instead:

$(thumbs).not(':first-child').fadeTo(1, inactiveOpacity)
         .end().filter(':first-child').addClass(clickedClass);

:first returns a single item which is index 0 in the result set. :nth-child(1) returns any item that is the first child of its parent, which is subsequently, the first li in each list.

Important: When using :nth-child it is important to realize that the number passed to the selector is 1 based, not 0 based like most arrays or selectors. :nth-child(1) is the first child, :nth-child(2) is the second, and so forth.

Thanks Nick!