Replace the default search with an HTML5 version

wordpress-html5-search

function search_form( $form ) {
    $form = '<form role="search" method="get" id="searchform" action="' . home_url( '/' ) . '" >
    <label for="s">' . __('Search for:') . '</label>
    <input type="search" placeholder="'.__("Enter keyword...").'" value="' . get_search_query() . '" name="s" id="s" />
    <input type="submit" id="searchsubmit" value="Search" />
    </form>';

    return $form;
}
add_filter( 'get_search_form', 'search_form' );