Question

I’m sure it’s a simple problem, and has an obvious answer, but the fact of the matter is I can’t work it out. Basically, if the div is clicked, and the variable exists, do this, if not, do that. But none of it works.

Ideas?

$("#lisea").click(
            var set = false;
            if(set) {
                function() {
                    $("body").animate({
                    opacity: 1
                    }, 500);
                    var set = false;
                }
            }
            if(!set) {
                function() {
                    $("body").animate({
                    opacity: 0.25
                    }, 500);
                    var set = true;
                }
            }
        );

Answer 1

You need your code inside a callback function – not just as a parameter. You’re also just defining a function in your condition – you need to invoke it.

Anyway I think this is probably what you want:

var set = false;
$("#lisea").click(function(){
    $('body').stop().animate({
        opacity: (set) ? 1 : 0.25
    }, 500);
    set = !set;
});

Here’s a demo: http://jsfiddle.net/upqTZ/