How do you read CSS rule values with JavaScript?

I would like to return a string with all of the contents of a CSS rule, like the format you'd see in an inline style. I'd like to be able to do this without knowing what is contained in a particular rule, so I can't just pull them out by style name (like .style.width etc.)

The CSS:

.test {
    width:80px;
    height:50px;
    background-color:#808080;
}

The code so far:

function getStyle(className) {
    var classes = document.styleSheets[0].rules || document.styleSheets[0].cssRules
    for(var x=0;x<classes.length;x++) {
        if(classes[x].selectorText==className) {
            //this is where I can collect the style information, but how?
        }
    }
}
getStyle('.test')