This is really for webusers creating documents with NewsPublisher+MaxiGallery.
Sorry, BobRay, still no luck.
Update:
So, I solved it with UserPlaceholders
As I already mentioned I added line
$modx->setPlaceholder('user.id', stripslashes($currentWebUser['id']));
in the snippet.
And here’s the solution:
[[UserPlaceholders]]
[+phx:if=`-[+user.id+]`:ne=`[*createdby*]`:then=``:else=`<center>[+managebutton+]</center><br/>`+]
I just put a minus before [+user.id+] because webusers in modx have negative values. That’s it.