strange else if

[Lionel]

never mind ...

[Andreas]

= is assignment, == is comparison
So the else if below thatsite will never be executed, eg. is useless.

In other words:
The code you posted is equivalent to

if ($scr == 1)
{
header ("Location: http://thissite");
}
else
{
$id = $_GET['id'];
header("Location: http://thatsite");
}

[Lionel]

Thanks. I had found out the problem. I was not sending the $scr in the link, so there was nothing to read ...