Style plugin

[cyberphr]

I want to create a plugin, basically to tell the user that the current theme is not supported, unless it is a certain styleid, or the default theme.

So yes, could someone give me a PHP or XHTML query for this? Something to the effect of:
<if $styleid != 1>This theme is not supported.</if>

[Dismounted]

<if condition="$vbulletin->session->vars['styleid'] != 1">This theme is not supported.</if>

[cyberphr]

Thank you, but I've already figured out a PHP method. A more basic method, too.

https://vborg.vbsupport.ru/showthread.php?p=1267577