// These scripts save a cookie for each visited image
// so a darker image can be used to replace the visited image on main page

function setCookie(name, value, expires, path, domain, secure) {
// default expiration time to 5 minute
 this.$expiration = new Date((new Date()).getTime() + 300000);
 
 var curCookie = name + "=" + escape(value) +
//     ((expires) ? "; expires=" + expires.toGMTString() : this.$expiration.toGMTString()) +
     ((expires) ? "; expires=" + expires.toGMTString() : "") +
     ((path) ? "; path=" + path : "") +
     ((domain) ? "; domain=" + domain : "") +
     ((secure) ? "; secure" : "");
 document.cookie = curCookie;
}

function getCookie(name) {
 var dc = document.cookie;
 var prefix = name + "=";
 var begin = dc.indexOf("; " + prefix);
 if (begin == -1) {
   begin = dc.indexOf(prefix);
   if (begin != 0) return null;
 } else
   begin += 2;
 var end = document.cookie.indexOf(";", begin);
 if (end == -1)
   end = dc.length;
 return unescape(dc.substring(begin + prefix.length, end));
}

function checkForVisited(link) {
 if (getCookie("visited")!=null) {
   var arr=getCookie("visited").split("&");
   for (i=0;i<arr.length;i++) {
     if (arr[i]==link) {
       return true;
     }
   }
   return false;
 } else return false;
}

function addVisited(link) {
 if (checkForVisited(link)) {
   return;
 } else {
   if (getCookie("visited")==null) {
     setCookie("visited", link);
   } else {
     var visitedLinks=getCookie("visited");
     visitedLinks+="&"+link;
     setCookie("visited", visitedLinks);
   }
 }
}

function loadImage(pImage, pAlt, pRowSpan, pColSpan, pVSpace, pHSpace) {
  var iFileName = 'images/' + pImage + '_t.jpg';
  var vFileName = 'images/' + pImage + '_d.jpg';
  var tWidth = 80 + 90 * ( pRowSpan - 1 );
  var tHeight = 80 + 95 * ( pColSpan - 1 );
  var tVSpace = pVSpace;
  var tHSpace = pHSpace;
  var tBorder = 1;

  if (checkForVisited(pImage)) {
    window.document.write('<IMG NAME="' + pImage + '" SRC="' + vFileName + '" ALT="' + pAlt + 
                          '" WIDTH="' + tWidth + '" HEIGHT="' + tHeight + 
                          '" BORDER="' + tBorder + '" VSPACE="' + tVSpace + 
                          '" HSPACE="' + tHSpace + '">');
  } else {
    window.document.write('<IMG NAME="' + pImage + '" SRC="' + iFileName + '" ALT="' + pAlt + 
                          '" WIDTH="' + tWidth + '" HEIGHT="' + tHeight + 
                          '" BORDER="' + tBorder + '" VSPACE="' + tVSpace + 
                          '" HSPACE="' + tHSpace + '">');
  }
}