function lang_change( lang ) {
	var page_url = document.location.href, slashes, winUrl;
	/* az utolsó 3 slasht levágjuk az url-ből: http://.../lang/public/... */
	for ( i = 3; 0 < i; i-- ) {
		page_url = page_url.substring( 0, page_url.lastIndexOf('/') );
	}
	slashes = page_url.split('/');

	/* ha nem éles oldalon vagyunk */
	if ( slashes && 3 < slashes.length ) {
		winUrl = page_url;
	}
	/* ha éles oldalon vagyunk */
	else {
		if ( lang != "ch-gb" && lang != "ch-big5" && lang != "cn" ) {
			winUrl = "http://www.eastinfo.hu";
		}
		else {
			winUrl = "http://eastinfo.org.cn";
		}
	}
	document.location.href = winUrl+"/"+lang;
//	alert(winUrl+"/"+lang+"/public/");
}