function popImage(url) {
	img_html = '<img src="' + url + '" />'
	//return overlib(img_html, VAUTO, HAUTO)
    return overlib(img_html, CENTER)
}

function hideElement(elementName) {
    document.getElementById(elementName).style.display = "none";
}
function showElement(elementName) {
    document.getElementById(elementName).style.display = "block";
}

function switchElementDisplay(elementName) {
    //console.info("element: " + document.getElementById(d).style);
    //console.info("display: " + document.getElementById(d).style.display);
    //alert(document.getElementById(d).currentStyle.display);

    var element = document.getElementById(elementName); 

    // get style
    var style;
    if(typeof element.currentStyle != 'undefined') {
        style = element.currentStyle;
    } else if (typeof document.defaultView.getComputedStyle != 'undefined') {
        style = document.defaultView.getComputedStyle(element, null);
    }

    // if style is retrieved
    if (style != null) {
        if (style.display == 'block') {
            element.style.display = 'none';
        } else {
            element.style.display = 'block';
        }
    } else {
        element.style.display = 'block';
    }
}