// http://www.w3.org/TR/wai-aria/roles#landmark_roles
function addARIARole(strID, strRole)
{
    // Find the element to add a role property to
    var objElement = document.getElementById(strID);

    if (objElement)
    {
        // Add the role property to the element
        objElement.setAttribute('role', strRole);
    }
}
function setupARIA()
{
    // Add ARIA roles to the document
    addARIARole('content', 'main');
    addARIARole('nav', 'navigation');
    addARIARole('search', 'search');
    addARIARole('site-title', 'banner');
}

window.onload = setupARIA;