<?php

switch ($form['#id']) {
    case 'views-exposed-form-search-page-search-page':
      $form['actions']['#attributes']['class'][] = 'input-group-btn';
      $form['actions']['submit']['#attributes']['class'][] = 'icon glyphicon glyphicon-search';
      $form['actions']['submit']['#value'] = '';
      $form['keys']['#attributes']['data-toggle'] = 'tooltip';
      $form['keys']['#attributes']['placeholder'] = 'Search in Blogs';
      $form['keys']['#attributes']['title'] = 'Search in Blogs';
      break;
  }