$form['button4'] = array(
'#value' => 'RESET',
'#type' => 'submit',
'#submit' => array('form_test_form_button4'),
'#ajax' => array(
  'callback' => 'ajax_example_submit_driven_callback1',
   'progress' => array('type' => 'none'),
    wrapper' => 'deletevalue',
),

);