CSS BlockUI

CSS BlockUI

On BlockUI can i pass the CSS as parameter instead? 

This is the normal :
$.blockUI({css: { border: 'none', padding: '5px', backgroundColor: '#000', '-webkit-border-radius': '5px', '-moz-border-radius': '5px', opacity: .5, color: '#fff' }, message: "Loading..."});

I created the class in CSS file : 
.blockui {
    border: none;
    padding: 5px;
    background-color: #000;
    -webkit-border-radius: 5px;
    -moz-border-radius: 5px;
    opacity: .5;
    color: #fff;
}

and I what to pass to block using the class

$.blockUI({css: '.blockui', message: "Loading..."});

this one way to do this?