html php isset,PHP/HTML - isset function

If $id is not set, the call to setdefault($id,0) will generate a warning. A function like setdefault does not work in PHP. Use this instead.

if (!isset($id)) $id = 0;

If you are doing this for array variables, like $_GET and $_POST, you can do this:

function getuservar($A, $index, $default = '') {

if (!isset($A[$index])) return $default;

if (get_magic_quote_gpc()) return stripslashes($A[$index]);

return $A[$index];

}

$clean_id = getuservar($_GET, 'id', 0);

This return form is better because you stop using the $_GET array immediately and only use the variables that are cleaned in the rest of the code. You clean your external variables once and never touch the external variables again in your code. $A can be $_GET, $_POST, $_REQUEST or $_COOKIE.

It also handles the annoying magic_quote stuff for you so you know the data in the variable is the text sent by the user. Just remember to clean it again when sending it back to the user or to the database.