PHP header location-redirect doesn't work - why? [duplicate]

Here's my file. I want to make it redirect, but nothing happens. To check out what is going on, I added an echo before the header part.

It neither throws an error or redirect to index.php. What is wrong? I have turned output buffering on/off, but nothing makes it redirect. What can I do?

<?
error_reporting(E_ALL);
echo 'This is an error';

header("Location: login.php");
die();
?>

Thanks

From PHP documentation :

header() must be called before any actual output is sent, either by normal HTML tags, blank lines in a file, or from PHP.

And in your case, you are using echo before header()

I reminded myself that I had xDebug installed on the actual test environment and after googling it, I found this site: http://bugs.xdebug.org/view.php?id=532

So I'll downloaded the last version of xDebug and changed the php.ini accordingly for the new file and everything works out like a charm. Headers are being sent - the redirecetion is done and errors are displayed.

Thanks everybody for your help!

Do you have short tags enabled? try it with the long tag <?php:

<?php
error_reporting(E_ALL);
header("Location: login.php");
die();
?>