php - URL lost during POST -

what's wierd on 1 page can echo variable built by:

$protocol = strpos(strtolower($_server['server_protocol']),'https') === false ? 'http' : 'https'; $host     = $_server['http_host']; $script   = $_server['script_name']; $params   = $_server['query_string']; $currenturl = $protocol . '://' . $host . $script . '?' . $params; 

then post page (i know post works because send other values):

<?php echo'<input type="hidden" name="refferer" value="'.$currenturl.'"/>'?> 

but when try use on other page empty:

$return = $_post[refferer]; header("location: $return"); 

anyone know what's happening it?

try:

$return = $_post['refferer']; header("location: $return");