function loader(url)
{
 eScript = document.createElement("script");
 eScript.setAttribute("language", "javascript");
 document.getElementById("loaderJS").appendChild(eScript);
 eScript.setAttribute("src", url);
}

var url = "portal.navigation_menu.build_tree?p_page_group=<gid>&p_page_id=<pid>&p_menu_id=d&p_display_title=&p_show_desc=N&p_show_page_image=N&p_show_one_level=Y";

var x = document.getElementsByTagName("DIV");
var tmp, pageid, groupid;

for(var i=0; i<x.length; i++)
{
	tmp = x[i].id.split("_")

	if(tmp.length == 5)
	{
		groupid = tmp[2]
		pageid = tmp[3]
		break
	}
}

document.write("<div id='loaderJS' class='dtree'></div>");

url = url.replace("<gid>", groupid);
url = url.replace("<pid>", pageid);
//alert(url);
//window.open(url, '_blank', null)
loader(url);