function mark(block) {
/*
    try {
        d = document.getElementById(cblock);
        d.style.visibility = 'hidden';
    } catch (e) {
    }
*/
    d = document.getElementById(block);
    d.style.visibility = 'visible';
}

function unmark(block) {
    d = document.getElementById(block);
    d.style.visibility = 'hidden';
}

function search(f,type) {
    id = f.options[f.options.selectedIndex].value;
    document.location.href="?st="+type+"&id="+id;
}