useful function when you need to import js without html...

using js to import js

function loadJS(url,loadFinished){
	if(typeof loadFinished != 'function')
		loadFinished=function(){};

	rs_nav.message("JS from "+url+" start to load...");

	var JS = document.createElement('script');
	JS.setAttribute('src', url);
	if (document.getElementsByTagName('head').item(0) == null)
		document.getElementsByTagName('html').item(0).appendChild(document.createElement('head'));

	JS.onload = function(){
		rs_nav.message("JS from "+url+" is loaded!");
		loadFinished();
	};
	JS = document.getElementsByTagName('head').item(0).appendChild(JS);
}