add expires = 300 days when set cookie

@@ -178,7 +178,9 @@ a:active {
   }
 
   function setCookie(name,value){
-      document.cookie = name + "=" + value + "; "
+      var exp = new Date(); 
+      exp.setTime(exp.getTime() + 3000*24*60*60*1000);
+      document.cookie = name + "=" + value + ";expires=" + exp.toGMTString();
   }
 	
   function onOpen(evt)