Jquery if & else statement for visible and hidden

Hey all,

I'm working on a summer project for university, and I am 99% finished on it, there is just one small thing that I am stuck on;

I have a navigation system with a sub menu within one of the anchors, the sub menu has fadeIn on it when you click on the anchor, and so what I am after is;

When the sub menu is visible, I need the homepage opacity to drop to 25%, and when the sub menu is hidden I need the homepage opacity to come back to 100%

I thought this was possible through an If, else statement but as I am a novice I am unsure of this, and so far got this;

Code:

$("#cat").click(function(){
 if ($('.sub1').is(':visible') ) {
 $(".homepage").fadeTo(500, .25);}

 else {
 $(".homepage").fadeTo(500, 1);

 }

I have also tried this via .CSS which partially works, when the sub menu is visible the Homepage opacity drops but then when I click #cat and the sub menu is hidden, the homepage won't come back to 100% opacity ;

Code:

$("#cat").click(function(){
    if ($('.sub1').css('opacity') == .25 ) {  

        $('.homepage').fadeTo(500, 1);

    } else {

        $('.homepage').fadeTo(500, .25); 
    }
});

 

Could this help: http://api.jquery.com/toggle-event/

 

might help, I suggest w3school