Add wmode query variable to iframe source with jQuery

jQuery - add wmode to iframe source

$('iframe').each(function() {
    var source = $(this).attr('src');
    var wmode = "wmode=opaque";
    if (source.indexOf('?') != -1) {
        $(this).attr('src', source + '&' + wmode);
    } else {
        $(this).attr('src', source + '?' + wmode);
    }
});