Boolean login = false;
  while(read.nextLine() !=null){
    String user = read.next();
    String pass = read.next();
    read.next();
  if(usernameT.getText().equals(user) &&
    passwordT.getText().equals(pass)){
  login = true;
  break;
   }
 }
if(login)
new Menu();
else {
JOptionPane.showMessageDialog(null, "Incorrect
username or password");
usernameT.setText("");
passwordT.setText("");
 }