A redirect to another PHP script

I need to redirect to a specific PHP file depending on the content of a variable, for example, in case the variable $action has a 1 then go to page add.php3, 2 then redirect to page modify.php3, etc. How could I go about doing this? Thanks in advance

You can use the header("Location: url"); to redirect, as long as you do it before sending anything to the output stream (i.e. HTML or print/echo).

If you only have a couple of possibilities for the redirect location I'd just use an if:

if ($action==1)
{
header("Location: add.php3");
exit;
}
header ("Location: modify.php3");
exit;

If you have a few to several pages you could use a switch/case construct.

But, if you have several values for $action, I'd use an array. You could set the array up in an included file for ease of editing.

// begin actionarray.php3
$url[1]="add.php3";
$url[2]="modify.php3";
$url[3]="whatever.php3";
etc.

Then in the main script (perhaps you want to check to see if $action is set first):

if (isset($action))
{
include ("actionarray.php3");
header("Location: $url[$action]");
exit;
}
//do something else