simple php variable question

for a newbie

[blind]

hey i have a small prob.

how do i intialise a variable.
i have a variable called $auth
and i want to write a litle something like

if ($auth == ""){
$auth=0; }

so if auth is equal to nothing set to 0
but i cant get this to work. help.

[DrDoc]

The simplest way would be to do something like this:

if(!$auth) {
$auth = 0;
}

[jatar_k]

there are a couple

if (empty($auth)) $auth = 0;
if (!isset($auth)) $auth = 0;

[blind]

ah cool works great thanks guys.