PHP: checking for $_GET variables with if statements
If it's a small app something like that would probably be better:

$getvar = isset($_GET['getvar']) ? $_GET['getvar'] : 'somedefault';


If you want to test more stuff:

$getvar = isset($_GET['getvar']) &amp;&amp; $JUST_PUT_IT_HERE ? $_GET['getvar'] : 'somedefault';