function kat() {
	var dropdown_kategorie = document["stoebern"].elements["kategorie"];
	kategorie = dropdown_kategorie.options[dropdown_kategorie.selectedIndex].value;

	if(kategorie == '-1') {
		document.forms['stoebern'].reset();
		document.forms['stoebern'].elements[0].blur();
		return;
	} else {
		parent.show.location.href = 'index.php?kategorieID=' + kategorie;
	}
}

function openwin(type, id) {
	switch (type) {
		case "autor":
			autor = window.open("autor.php?autorID=" + id,"autor","width=320,height=420,left=50,top=50" );
			autor.focus();
			break;
		case "kommentar":
			kommentar = window.open("kommentar.php?buchID=" + id,"kommentar","scrollbars=no,width=500,height=650,left=0,top=0" );
            kommentar.focus();
            break;
        case "reihe":
			kommentar = window.open("buchreihe.php?reiheID=" + id,"buchreihen","scrollbars=no,width=500,height=650,left=0,top=0" );
            kommentar.focus(); 
            break;
    break;
	}
}