function getCounterCookieVal(cookieName)

    {
	var allCookies = document.cookie;
	if(allCookies == "")
	{
		return -1;
	}
	var start = allCookies.lastIndexOf(cookieName + "=");
	if(start == -1)
	{
		return -1;	
	}
	start += (cookieName.length + 1);
	var end = allCookies.indexOf(';', start);
	if(end == -1)
	{
		end = allCookies.length;
	}
	if(isNaN(parseInt(allCookies.substring(start,end))))
	{
		return -1;
	}
	return allCookies.substring(start,end);
    }
	 
function writeCookie(szCookieName, nImageNum, nExpireDays)
    {
	var expiration = new Date((new Date()).getTime() + nExpireDays*86400000);
	var szCookie = szCookieName + "=" + nImageNum + "; path=" + "/" + "; expires=" + expiration.toGMTString() + ";";
	document.cookie = szCookie;
    }
	 
function runImageLookup()
    {
	var pictureNum = 0 - 0; 
	var cookieVal = getCounterCookieVal("IMAGECOUNT");
	
// this is the number of pictures that the script cycles through
	if((cookieVal < 0) || (cookieVal > 15)) 
	{
		cookieVal = 1;
	}
	
// to make pictureNum an integer
	pictureNum = cookieVal; 

// this is the source for the pictures, directory = photo, file = photo plus number

  document.writeln('<A HREF="photos/photo'
                 +pictureNum
                 +'.htm"><IMG SRC="photos/photo'
                 +pictureNum
                 +'.jpg" BORDER="0"></A>');
       
// -0 to force addition over concatenation
	pictureNum = pictureNum - 0 + 1; 
	
//cycle of photos set to 15
	if(pictureNum > 15) pictureNum = 1; 
	
// sets expiration date for the cookie
	writeCookie("IMAGECOUNT", pictureNum, 30); 
    }