Finding the actual computed value of a CSS Style Property on an Element

        <pre data-sub="prettyprint:_">
        // Get a style property (name) of a specific element (elem)
        function getStyle( elem, name )
        {
        // If the property exists in style[], then it's been set
        // recently (and is current)
        if (elem.style[name])
        {
        return elem.style[name];
        }
        // Otherwise, try to use IE's method
        else if (elem.currentStyle)
        {
        return elem.currentStyle[name];
        }
        // Or the W3C's method, if it exists
        else if (document.defaultView && document.defaultView.getComputedStyle)
        {
        // It uses the traditional 'text-align' style of rule writing,
        // instead of textAlign
        name = name.replace(/([A-Z])/g,"-$1");
        name = name.toLowerCase();
        // Get the style object and get the value of the property (if it exists)
        var s = document.defaultView.getComputedStyle(elem,"");
        return s && s.getPropertyValue(name);
        // Otherwise, we're using some other browser
        } else
        return null;
        }
        </pre>