function _GetCookie(name) 
{  
   var arg = name + "=";  
   var alen = arg.length;  
   var clen = document.cookie.length;  
   var i = 0;  

   while (i < clen) {    
      var j = i + alen;    
      if (document.cookie.substring(i, j) == arg)      
         return _getCookieVal(j);    
      i = document.cookie.indexOf(" ", i) + 1;    
      if (i == 0) 
         break;   
   }  
   return null;
}

function _SetCookie(name, value) 
{  
   var argv = _SetCookie.arguments;  
   var argc = _SetCookie.arguments.length;  
   var expires = (argc > 2) ? argv[2] : null;  
   var path = (argc > 3) ? argv[3] : null;  
   var domain = (argc > 4) ? argv[4] : null;  
   var secure = (argc > 5) ? argv[5] : false;  
   document.cookie = name + "=" + escape (value) + 
   ((expires == null) ? "" : ("; expires=" + expires.toGMTString())) + 
   ((path == null) ? "" : ("; path=" + path)) +  
   ((domain == null) ? "" : ("; domain=" + domain)) +    
   ((secure == true) ? "; secure" : "");
}

function _DeleteCookie (name) 
{  
   var exp = new Date();  
   exp.setTime (exp.getTime() - 10);  
   var cval = _GetCookie (name);  
   document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString();
}

function _getCookieVal(offset)
{
   var endstr = document.cookie.indexOf (";", offset);
   if (endstr == -1)
      endstr = document.cookie.length;
   return unescape(document.cookie.substring(offset, endstr));
}