var lightbox = document.getElementById('lightbox');
var blackout = document.getElementById('blackout');

function showLightbox(imgsrc, caption)
{
    document.lightbox.src=imgsrc;
    document.getElementById('caption').innerHTML = caption;

    hideSelects('hidden');

    blackout.style.top=document.body.scrollTop;
    blackout.style.display='block';

    lightbox.style.display='block';
    //lightbox.style.top='10%';
    //lightbox.style.left='25%';
    //lightbox.style.width='50%';
}

function hideLightbox()
{
    hideSelects('visible');
    lightbox.style.display='none';
    blackout.style.display='none';
}

function hideSelects(visibility)
{
    selects = document.getElementsByTagName('select');
    for(i = 0; i < selects.length; i++) {
        selects[i].style.visibility = visibility;
    }
}