if ((username != null && username !="") || (password != null && password !=""))
if ((username != null && !username.equals("")) || (password != null && !password.equals("")))
  public String getCommentForm(Integer itemId, Integer toId, String username, String password) throws RemoteException   {    int userId = -1;    String html = "";    UserLocalHome uHome;    ItemLocalHome iHome;    // Authenticate the user who want to comment      if ((username != null && username !="") || (password != null && password !=""))      {        SB_AuthLocalHome authHome = null;        SB_AuthLocal auth = null;        try         {          authHome = (SB_AuthLocalHome)initialContext.lookup("java:comp/env/ejb/SB_Auth");          auth = authHome.create();        }         catch (Exception e)        {          throw new RemoteException("Cannot lookup SB_Auth: " +e);        }        try         {          userId = auth.authenticate(username, password);        }         catch (Exception e)        {          throw new RemoteException("Authentication failed: " +e);        }        if (userId == -1)        {           html = (" You don't have an account on RUBiS!<br>You have to register first.<br>");           return html;        }      }    // Try to find the user corresponding to the 'to' ID    try     {      uHome = (UserLocalHome)initialContext.lookup("java:comp/env/ejb/User");      iHome = (ItemLocalHome)initialContext.lookup("java:comp/env/ejb/Item");    }     catch (Exception e)    {      throw new RemoteException("Cannot lookup User or Item: " +e+"<br>");    }    try    {      UserLocal    to = uHome.findByPrimaryKey(new UserPK(toId));      ItemLocal    item = iHome.findByPrimaryKey(new ItemPK(itemId));      String  toName = to.getNickName();      html = "<center><h2>Give feedback about your experience with "+toName+"</h2><br>\n" +        "<form action=\"/servlet/edu.rice.rubis.beans.servlets.StoreComment\" method=POST>\n"+        "<input type=hidden name=to value="+toId.intValue()+">\n"+        "<input type=hidden name=from value="+userId+">\n"+        "<input type=hidden name=itemId value="+itemId.intValue()+">\n"+        "<center><table>\n"+        "<tr><td><b>From</b><td>"+username+"\n"+        "<tr><td><b>To</b><td>"+toName+"\n"+        "<tr><td><b>About item</b><td>"+item.getName()+"\n";    }    catch (Exception e)    {      throw new RemoteException("Cannot build comment form: " +e);    }    return html;  }