Bootstrap(2.3.2) modal popup visibility check

Question

I need to insert a class name to body tag when the bootstrap pop up is opened. I have tried adding using jquery but unfortunately it is not working. Any help would be appreciated.

Here is my code

if(!$('.modal-backdrop').is(':visible'))
{
$(body).addClass("test");
}

Demo

Answer 1

$('.modal-backdrop').on('shown', function() {
        $('body').addClass("test");
    });

    $('.modal-backdrop').on('hidden', function () {
    $('body').removeClass("test");
})