I need the ability to load and start a GWT App at any time in an Echo2 environment. My first approach was to load and execute the nocache.js in a Client-Server sync using

var script = document.createElement("script");
script.setAttribute("src",javascriptURI);
script.setAttribute("type","text/javascript");
document.getElementsByTagName('body')[0].appendChild(script);

This call basically works, but when the script is executed it operates on an EMPTY document instead of the current document of the Echo2 application. Has the script to be somehow initialized first or is there any event required?

The GWT application/script works fine if it's included in the start-up HTML of the application, so I assume the GWT App to be correct. The original standalone HTML of the GWT App has the HTML script tag in the body as well.