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;    StringBuffer html      = new StringBuffer();    PreparedStatement stmt = null;    ResultSet rs           = null;    Connection conn        = null;    // Authenticate the user who want to comment    if ((username != null && username !="") || (password != null && password !=""))    {      SB_AuthHome authHome = null;      SB_Auth auth = null;      try       {        authHome = (SB_AuthHome)PortableRemoteObject.narrow(initialContext.lookup("java:comp/env/ejb/SB_Auth"), SB_AuthHome.class);        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.append(" You don't have an account on RUBiS!<br>You have to register first.<br>");        return html.toString();      }    }    // Try to find the user corresponding to the 'to' ID    String toName=null, itemName=null;    try    {      conn = dataSource.getConnection();      stmt = conn.prepareStatement("SELECT nickname FROM users WHERE id=?");      stmt.setInt(1, toId.intValue());      rs = stmt.executeQuery();      if (rs.first())        toName = rs.getString("nickname");      stmt.close();    }    catch (Exception e)    {      try      {        if (stmt != null) stmt.close();        if (conn != null) conn.close();      }      catch (Exception ignore)      {      }      throw new RemoteException("Failed to execute Query for user name: " +e);    }    try    {      stmt = conn.prepareStatement("SELECT name FROM items WHERE id=?");      stmt.setInt(1, itemId.intValue());      rs = stmt.executeQuery();      if (rs.first())        itemName = rs.getString("name");      if (stmt != null) stmt.close();      if (conn != null) conn.close();    }    catch (Exception e)    {      try      {        if (stmt != null) stmt.close();        if (conn != null) conn.close();      }      catch (Exception ignore)      {      }      throw new RemoteException("Failed to execute Query for item name: " +e);    }    try    {      html.append("<center><h2>Give feedback about your experience with "+toName+"</h2><br>\n");      html.append("<form action=\"/servlet/edu.rice.rubis.beans.servlets.StoreComment\" method=POST>\n");      html.append("<input type=hidden name=to value="+toId.intValue()+">\n");      html.append("<input type=hidden name=from value="+userId+">\n");      html.append("<input type=hidden name=itemId value="+itemId.intValue()+">\n");      html.append("<center><table>\n");      html.append("<tr><td><b>From</b><td>"+username+"\n");      html.append("<tr><td><b>To</b><td>"+toName+"\n");      html.append("<tr><td><b>About item</b><td>"+itemName+"\n");    }    catch (Exception e)    {      throw new RemoteException("Cannot build comment form: " +e);    }     return html.toString();  }