function ReadCookie(CookieName){
  var CookieString = document.cookie;
  var CookieSet = CookieString.split (';');
  var SetSize = CookieSet.length;
  var CookiePieces
  var ReturnValue = "";
  var x = 0;
  for (x = 0; ((x < SetSize) && (ReturnValue == "")); x++) {
    CookiePieces = CookieSet[x].split ('=');
    if (CookiePieces[0].substring (0,1) == ' ') {
      CookiePieces[0] = CookiePieces[0].substring (1, CookiePieces[0].length);
    }
    if (CookiePieces[0] == CookieName) {
      ReturnValue = CookiePieces[1];
    }
  }
  return ReturnValue;
}


function WriteCookie (cookieName, cookieValue, expiry) 
{
  var expDate = new Date();
  if(expiry)
  {
  expDate.setTime (expDate.getTime() + expiry);
    document.cookie = cookieName + "=" + cookieValue + "; expires=" 
                      + expDate.toGMTString();
  } else  {
        document.cookie = cookieName + "=" + escape (cookieValue);
  }
}