Two of them, actually.
1) if ($string == '' || null) can be improved as if (!$string)
2) $string is a poor variable name
3) if and statement on the same line is bad practice (the return can easily be overlooked when browsing through the code
4) Not using { and } is bad practice.
5) 'massage' should probably be 'message'
The code improved should be something like:
if (!$name) {
return 'No name given';
}