html:
<link id="dubboKeeperTheme" rel="stylesheet" href="" media="screen">
js:
function setTheme(themeName){
var themeUrl = "";
if('default'==themeName){
themeUrl="";
}else{
themeUrl="css/libs/themes/"+themeName+"/bootstrap.css"
}
window.document.getElementById('dubboKeeperTheme').setAttribute('href',themeUrl);
}