function Selecionar(sel, targetstr) {
    var index = sel.selectedIndex;
    if (sel.options[index].value != '') {
        if (targetstr == 'blank') {
            window.open(sel.options[index].value, 'win1');
        } else {
            var frameobj;
            if (targetstr == '') targetstr = 'self';
            if ((frameobj = eval(targetstr)) != null)
                frameobj.location = sel.options[index].value;
        }
    }
}