Vantage – Place Main Menu over the slider.

Is it at all possible to layer the main navigation menu over the slider?

What I’m trying to achieve is having a semi-transparent main navigation menu over the slider. However what I repeatedly end up with is a slider that is over the top of my menu.

I have used the following to move the slider up…

.flexslider .slides {
margin-top: -110px;
float: left;
clear: both;
}

What CSS do I need to add so that the menu is layered over the top of the slider. I have used the z-index to no avail.

Thanks,

Mark