can't get any string replacements to clean this

All i get out of: str_replace ereg_replace preg_replace is an empty string value. Anybody know why? <?PHP $bad_str = " \t\t\t\\r\\\r\r\r\r\n\r\nFour schore ...........and seven \n\n\n\n\nr\r\r\rn\r years ago, ,,,,,,, ,,,,,,,our father created on tis planet \t\t\t\\r\\\r\r\r\r\n\r\nFour "; echo( "<br>\nuncleaned string-------------------------------------<br>\n"); echo($bad_str . "<br>\nn" ); echo( "<br>\ncleaned --------------------------------------------<br>\n"); //Nothing will clean on this line $bad_str = preg_replace( '\r', '\n', $bad_str ); echo("</pre>\n"); ?>