function display_filter()
{
    try
    {
        document.getElementById('filter-box').style.display='block';
        document.getElementById('filter-display-link').style.display='none'; 
    }
    catch(e) { /* ignore */ }
}

function hide_filter()
{
    try
    {
        document.getElementById('filter-box').style.display='none';
        document.getElementById('filter-display-link').style.display='block'; 
    }
    catch(e) { /* ignore */ }
}

function display_manufacturers()
{
    try
    {
        document.getElementById('manufacturer-box').style.display='block';
        document.getElementById('manufacturer-hide-link').style.display='inline';
        document.getElementById('manufacturer-show-link').style.display='none';
    }
    catch(e) { /* ignore */ }
}

function hide_manufacturers()
{
    try
    {
        document.getElementById('manufacturer-box').style.display='none';
        document.getElementById('manufacturer-show-link').style.display='inline';
        document.getElementById('manufacturer-hide-link').style.display='none';
    }
    catch(e) { /* ignore */ }
}

function display_filter_display_link()
{
    try
    {
        if(!location.href.indexOf('category.php?k_index'))
            document.getElementById('filter-display-link').style.display='block';
    }
    catch(e) { /* ignore */ }
}

function check_no_manufacturers()
{
    try
    {
        var arr = document.getElementsByTagName('input');
        for(var i=0;i<arr.length;i++)
        {
            if(arr[i].id.indexOf('manufacturer') != -1)
                arr[i].checked = false;
        }
    }
    catch(e) { /* ignore */ }
}

function check_all_manufacturers()
{
    try
    {
        var arr = document.getElementsByTagName('input');
        for(var i=0;i<arr.length;i++)
        {
            if(arr[i].id.indexOf('manufacturer') != -1)
                arr[i].checked = true;
        }
    }
    catch(e) { /* ignore */ }
}

function checkSelectedManufacturers(manufacturerIds)
{
    for(i=0; i<manufacturerIds.length; i++)
    {
        try
        {
            document.getElementById('manufacturer-' + manufacturerIds[i]).checked = true;
        }
        catch(e) { /* cannot check manufacturer */ }
    }
}