[jquery] jQuery CSS Opacity

What's wrong? I want to change the opacity if #nav .drop is display:block;

jQuery(document).ready(function(){
    if (jQuery('#nav .drop').css('display') === 'block') {
        jQuery('#main').css('opacity') = '0.6';
    }
});

Try this:

jQuery('#main').css('opacity', '0.6');

or

jQuery('#main').css({'filter':'alpha(opacity=60)', 'zoom':'1', 'opacity':'0.6'});

if you want to support IE7, IE8 and so on.

try using .animate instead of .css or even just on the opacity one and leave .css on the display?? may b

jQuery(document).ready(function(){
if (jQuery('#nav .drop').animate('display') === 'block') {
    jQuery('#main').animate('opacity') = '0.6';

Try with this :

jQuery('#main').css({ opacity: 0.6 });