Server Expression for PHP

[brain]

I'm trying to make a search engine using a tutrial but then I came to the point I had to fill in the Server Expression. Only these examples were given:

Application Server Expression
---------------------------------------------
ASP | Request("mnuDept") |
JSP | request.getParameter("mnuDept")|
ColdFusion | #mnuDept# |
---------------------------------------------

But there's nothing about PHP. Does anybody know what to fill in for PHP ?

Greetz

[Abstraction]

$mnuDept