function rntu_keywords_changed() {
	var select_variable = $('registration').category;
	var ausgewaehlte_Elemente = ""; 
	if(select_variable.selectedIndex > -1 ){
		for (var i = select_variable.selectedIndex;
			i < select_variable.length; i++) { 
			if (select_variable[i].selected) { 
				ausgewaehlte_Elemente += select_variable[i].text + "; "; 
			} 
		}

		$('registration').temporary_input_not_to_be_used.value = ausgewaehlte_Elemente;
		
	}
}