function includeCSSfile(href) {
    var head_node = document.getElementsByTagName('head')[0];
    var link_tag = document.createElement('link');
    link_tag.setAttribute('rel', 'stylesheet');
    link_tag.setAttribute('type', 'text/css');
    link_tag.setAttribute('href', href);
    head_node.appendChild(link_tag);
}
/* removed for wrong paths
if (navigator.userAgent.indexOf('Opera') >= 0) {			
	includeCSSfile("includes/bb_opera.css");
}else if(navigator.userAgent.indexOf('Safari') >= 0){			
	includeCSSfile("includes/bb_safari.css");
}*/