function filter_news()
{
	var categories = '';
	var subject = document.getElementById('thema');
	// nun weitere Felder auslesen, z.B. Medientyp
	var mediaType = document.getElementById('medienTyp');
	var author = document.getElementById('author');
 
	categories = subject + ',' + mediaType + ',' + author;
 
	// neue URL mit Variable 'categories' zusammen setzen
	window.location = document.getElementById('filter-formular').action +
		'?no_cache=1&categories=' + categories;
}