PHP Search the Vowels Used

Post your code, so I can help you to find the problem

echo preg_replace('~[^aeiou]~i', '', 'i love you')

should remove all non vowel character. I haven't tested it yet but I might be start.

Don't think he wants to remove them, just identify them.

Do you want to include accented characters like â? If so, should they be listed separately or slugified (â,à etc = a, ô etc = o).

Are the vowels supposed to be case-sensitive?

$text = 'Hi AlaôyÖ!  know the way to K\'ôêìlp';
$text = strtolower(preg_replace('~[^-\w]+~', '', iconv('utf-8', 'us-ascii//TRANSLIT', $text)));
$check = array('a','e','i','o','u');
foreach($check as $chk){
	if(strpos($text,$chk) !== false){
		$ans[] = $chk;	
	}
}
if(isset($ans)){
	$comment = "Vowels in this string: " . implode(", ",$ans); 
}else{
	$comment = "No vowels were found in this string";	
}
echo $comment;

preg_match_all('/[aeiou]+/i', 'i love you', $arr, PREG_PATTERN_ORDER);

heres a cool tester.
http://www.solmetra.com/scripts/regex/index.php