function hide(div) {
    if (document.getElementById(div).style.display == 'none') {
        document.getElementById(div).style.display = 'block';
    }
    else {
        document.getElementById(div).style.display = 'none';
    }
}

function ask(question, url) {
    if (confirm(question)) {
        window.location.href = url;
    }
}
function select_all(id, num)
{   
    for(var j = 1; j <= num; j++) {
        box = document.getElementById(id + j);
        if (box.checked == false) {
            box.checked = true;
        }
        else {
            box.checked = false;
        }
    }
}