<?php

// your code goes here

function clean($string) {
	eval('$string = "'.$string.'";');
   $string = str_replace(' ', ' ', $string); // Replaces all spaces with hyphens.
   return preg_replace('/[^A-Za-z0-9 @\-]/', '', $string); // Removes special chars.
}

$d =  clean('this was readlly n'ice 'test for@me to') ;
echo $d;