var has_inner = typeof(window.innerWidth) == 'number';
var has_element = document.documentElement
    && document.documentElement.clientWidth;

// Moves the box object to be centered on current
// viewable area of the page
function center_box(box, width, height)
{
    cleft = has_inner
        ? pageXOffset + 
          (window.innerWidth - width)/2
        : has_element
          ? document.documentElement.scrollLeft + 
            (document.documentElement.clientWidth - width)/2
          : document.body.scrollLeft + 
            (document.body.clientWidth - width)/2;

    ctop = has_inner
        ? pageYOffset + (window.innerHeight - height)/2
        : has_element
          ? document.documentElement.scrollTop + 
            (document.documentElement.clientHeight - height)/2
          : document.body.scrollTop + 
            (document.body.clientHeight - height)/2;

    box.style.left = cleft > 0 ? cleft + 'px' : '0px';
    box.style.top = ctop > 0 ? ctop + 'px' : '0px';
}

// Hides other alone popup boxes that might be displayed
function hide_other_alone(obj)
{
    if (!document.getElementsByTagName)
        return;

    var all_divs = document.body.getElementsByTagName("DIV");

    for (i = 0; i < all_divs.length; i++)
    {
        if (all_divs.item(i).style.position != 'absolute' ||
            all_divs.item(i) == obj ||
            !all_divs.item(i).alonePopupBox)
        {
            continue;
        }

        all_divs.item(i).style.display = 'none';
    }
    return;
}

// Shows a box if it wasn't shown yet or is hidden
// or hides it if it is currently shown
function show_hide_centered_box(an, width, height, borderStyle)
{
    show_hide_centered_href(
        an.href, width, height, borderStyle);
    return false;
}

// Shows a box if it wasn't shown yet or is hidden
// or hides it if it is currently shown
function show_hide_centered_href(href, width, height, borderStyle)
{
    var boxdiv = document.getElementById(href);

    if (boxdiv != null)
    {
        if (boxdiv.style.display=='none')
        {
            hide_other_alone(boxdiv);
            // Show existing box, move it
            // if document changed layout
            center_box(boxdiv, width, height);
            boxdiv.style.display='block';

            // Workaround for Konqueror/Safari
            if (!boxdiv.contents.contentWindow)
                boxdiv.contents.src = href;
        }
        else
            // Hide currently shown box.
            boxdiv.style.display='none';
        return false;
    }

    hide_other_alone(null);

    // Create box object through DOM
    boxdiv = document.createElement('div');

    // Assign id equalling to the document it will show
    boxdiv.setAttribute('id', href);

    // Add object identification variable
    boxdiv.alonePopupBox = 1;

    boxdiv.style.display = 'block';
    boxdiv.style.position = 'absolute';
    boxdiv.style.width = width + 'px';
    boxdiv.style.height = height + 'px';
    boxdiv.style.border = '1px solid #000000';
    boxdiv.style.textAlign = 'right';
    boxdiv.style.padding = '22px';
    boxdiv.style.background = '#E7E7E7';
    document.body.appendChild(boxdiv);

    var offset = 0;

    // Remove the following code if 'Close' hyperlink
    // is not needed.
    var close_href = document.createElement('a');
    close_href.href = 'javascript:void(0);';
    close_href.onclick = function()
    {
        show_hide_centered_href(href, width, height, borderStyle);
    }

    close_href.appendChild(document.createTextNode('Close'));
    boxdiv.appendChild(close_href);
    offset = close_href.offsetHeight;
    // End of 'Close' hyperlink code.

    var contents = document.createElement('iframe');
    //contents.scrolling = 'no';
    contents.overflowX = 'hidden';
    contents.overflowX = 0;
    contents.overflowY = 'scroll';
    contents.frameBorder = '0';
    contents.style.width = width + 'px';
    contents.style.height = (height - offset) + 'px';

    boxdiv.contents = contents;
    boxdiv.appendChild(contents);

    center_box(boxdiv, width, height);

    if (contents.contentWindow)
        contents.contentWindow.document.location.replace(
            href);
    else
        contents.src = href;

    // The script has successfully shown the box,
    // prevent hyperlink navigation.
    return;
}