var g_openZoom = 0;
var g_pageWidth = 1024;

function clickZoomable(id, imgWidth, imgHeight)
{
    if (g_openZoom == 0)
    {
        var shadeborder = 8;

        var elmShade = document.getElementById("zoomImageShade");
        var elmImage = document.getElementById("zoomImage" + id);
        var elmCloseButton = document.getElementById("closeButton" + id);

       // var imgX = g_pageWidth / 2 - imgWidth / 2;
				var imgX = Math.round( (viewportGetWidth() - imgWidth)/2 );
        var imgY = Math.round( (viewportGetHeight() - imgHeight)/2 ) + viewportGetScrollY();

        if (imgY < 0) { imgY = 0; }
        // if (imgX < 0) { imgX = 0; }

        elmShade.style.left = (imgX - shadeborder) + "px";
        elmShade.style.width = (imgWidth + shadeborder * 2) + "px";
        elmShade.style.top = (imgY - shadeborder) + "px";
        elmShade.style.height = (imgHeight + shadeborder * 2) + "px";

        elmImage.style.left = imgX + "px";
        elmImage.style.top = imgY + "px";
        if (elmCloseButton) {
            elmCloseButton.style.left = (imgWidth - 19) + "px";
        }

        elmImage.style.display = "block";
        elmShade.style.display = "block";

        g_openZoom = id;
				
				document.body.onclick = function () {clickZoomed("1");};
    }
				
}

function clickZoomed(fromBody)
{
	if (typeof(fromBody)=="string"){
			document.body.onclick = function () {clickZoomed();};
			return;
			}
		document.body.onclick = "";
    hideLr("zoomImageShade");
    hideLr("zoomImage" + g_openZoom);
    g_openZoom = 0;
}


function viewportGetHeight()
{
    var retval = 0;

    if (window.innerHeight)
        retval = window.innerHeight - 18;
    else if (document.documentElement && document.documentElement.clientHeight) 
        retval = document.documentElement.clientHeight;
    else if (document.body && document.body.clientHeight) 
        retval = document.body.clientHeight;

    return retval;    
}

function viewportGetWidth()
{
    var retval = 0;

    if (window.innerWidth)
        retval = window.innerWidth - 18;
    else if (document.documentElement && document.documentElement.clientWidth) 
        retval = document.documentElement.clientWidth;
    else if (document.body && document.body.clientWidth) 
        retval = document.body.clientWidth;

    return retval;    
}

function viewportGetScrollY()
{
    var retval = 0;

    if (typeof window.pageYOffset == "number")
        retval = window.pageYOffset;
    else if (document.documentElement && document.documentElement.scrollTop)
        retval = document.documentElement.scrollTop;
    else if (document.body && document.body.scrollTop) 
        retval = document.body.scrollTop; 
    else if (window.scrollY)
        retval = window.scrollY;

    return retval;
}

function hideLr(id)
{
    var elm = document.getElementById(id);
    if (elm) {
        elm.style.display = "none";
    }
}