function getBrowserWidth() {
    if (document.all) {
        return (document.body.clientWidth);
    } else {
        return (window.innerWidth);
    }
}

function hideIfNarrowScreen (doc_id, min_width) {
    var curr_width = getBrowserWidth();
    
    if (curr_width < min_width) {
        disappearObject(doc_id);
    } else {
        appearObject(doc_id);
    }
}

function showObject(object) {
    if (document.getElementById) {
        document.getElementById(object).style.visibility = 'visible';
    }
    else if (document.layers && document.layers[object]) {
        document.layers[object].visibility = 'visible';
    }
    else if (document.all) {
        document.all[object].style.visibility = 'visible';
    }
}

function hideObject(object) {
    if (document.getElementById) {
        document.getElementById(object).style.visibility = 'hidden';
    }
    else if (document.layers && document.layers[object]) {
        document.layers[object].visibility = 'hidden';
    }
    else if (document.all) {
        document.all[object].style.visibility = 'hidden';
    }
}

function appearObject(object) {
    if (document.getElementById) {
        document.getElementById(object).style.display = 'block';
    }
    else if (document.layers && document.layers[object]) {
        document.layers[object].display = 'block';
    }
    else if (document.all) {
        document.all[object].style.display = 'block';
    }
}

function disappearObject(object) {
    if (document.getElementById) {
        document.getElementById(object).style.display = 'none';
    }
    else if (document.layers && document.layers[object]) {
        document.layers[object].display = 'none';
    }
    else if (document.all) {
        document.all[object].style.display = 'none';
    }
}