Create sub-site in Sharepoint 2013 using JSOM?

var rootSite = "https://siteURL.com";

var ctx = new SP.ClientContext(rootSite);

var web = ctx.get_web();

var webInfo = new SP.WebCreationInformation();

webInfo.set_title('New Sub Site Title');

webInfo.set_description('sub site description');

webInfo.set_url('SubSiteURL');

webInfo.set_webTemplate('STS#0');

webInfo.set_useSamePermissionsAsParentSite(true);

webInfo.set_language(1033);

web.get_webs().add(webInfo);

web.update();

ctx.executeQueryAsync(function(){

console.log("Sub Site Created Successfully");

function(sender, args){

console.log("Sub Site Creation failed with error : " + args.get_message());

}

);