//add stylesheet on demand

//keep track of stylesheets added with this array
var css_list = new Array();

function add_stylesheet(ss_url) {
//check if stylesheet already added with this function
var stylesheet_found = false;
for (var i=0;i<css_list.length;i++) {
	if (css_list[i] == ss_url) {
		stylesheet_found = true;
	}
}	

if (!stylesheet_found) {
	css_list.push(ss_url);
	if(document.createStyleSheet) {

			document.createStyleSheet(ss_url);
	}

	else {

		var styles = "@import url('" + ss_url + "');";

		var newSS=document.createElement('link');

		newSS.rel='stylesheet';

		newSS.href='data:text/css,'+styles;

		document.getElementsByTagName("head")[0].appendChild(newSS);
	}
}
}

//adds a javascript file on demand
function add_js(id,js_file) { 

script = document.createElement('script');
script.id = id;
script.type = 'text/javascript';
script.src = js_file;
document.getElementsByTagName("head")[0].appendChild(script);
}