is valid page

A little function I use to double check the items in a friendly url to see if they only use valid characters.

// Check if the page name is correct
function isValidPage($page){
        $safe = array('a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','1','2','3','4','5','6','7','8','9','0','-','_','.');
        $pageCheck = preg_split('//', strtolower($page), -1, PREG_SPLIT_NO_EMPTY);
 
        // Make sure that the page name has only safe variables
        foreach($pageCheck as $key => $val){
                if(!in_array($val, $safe)) return false;
        }
        return true;
}

// Check if the page name is correct
function isValidPage($page){
	$safe = array('a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','1','2','3','4','5','6','7','8','9','0','-','_','.');
	$pageCheck = preg_split('//', strtolower($page), -1, PREG_SPLIT_NO_EMPTY);

	// Make sure that the page name has only safe variables
	foreach($pageCheck as $key => $val){
		if(!in_array($val, $safe)) return false;
	}
	return true;
}