function navi(form)
{
	var form_urls = new Array(
	'4037324', //przetargi
	'4048919', // zamowienia UE
	'4100623', // komunikaty
	'4100637', // ruchomosci
	'4100641'  // nieruchomosci
	); 
	
   var w = form.announcementTypeAlias.selectedIndex;
   var port = window.location.port;
   if (port == 80) {
		port = '';   
   } else {
	   port = ':' + port;
   }
   var url_add = window.location.protocol + '//' + window.location.hostname + port + '/komunikaty/0,79736,' + form_urls[w] + '.html';
   window.location.href = url_add;
}