Get a button for <hr> in the Editor

Somehow the WordPress editor doesn’t have a button to insert a horizontal line (<hr /> in html). Is there a plugin that adds this button? Or an easy way to add such a button myself?

Solutions Collecting From Web of "Get a button for <hr> in the Editor"

There’s an easy way.
Open functions.php and add this code. It works for many html entities

// got this form

function enable_more_buttons($buttons) {
  $buttons[] = 'hr';

  Repeat with any other buttons you want to add, e.g.
  $buttons[] = 'fontselect';
  $buttons[] = 'sup';

 return $buttons;

add_filter("mce_buttons", "enable_more_buttons");
//add_filter("mce_buttons_2", "enable_more_buttons"); // add to second row
//add_filter("mce_buttons_3", "enable_more_buttons"); // add to third row