add buttons to visual editor

function extra_editor_buttons($buttons){
	$buttons[] = 'wp_page'; //wp page
	$buttons[] = 'cut'; //cut – crtl + x
	$buttons[] = 'copy'; // copy – crtl + c
	$buttons[] = 'paste'; //paste – crtl + v
	$buttons[] = 'newdocument'; //clear all
	$buttons[] = 'code'; //code block
	$buttons[] = 'cleanup'; // clean styleing
	$buttons[] = 'styleselect'; //select style
	$buttons[] = 'fontselect'; //select font
	$buttons[] = 'backcolor'; // back color
	$buttons[] = 'image'; 
	$buttons[] = 'media';
	$buttons[] = 'anchor'; //anchor tag
	$buttons[] = 'sub'; // sub-text
	$buttons[] = 'sup'; // sup-text
	$buttons[] = 'hr'; 
 	return $buttons;
}
add_filter("mce_buttons_3", "extra_editor_buttons");