Hello,
The following error:
Cannot modify header information - headers already sent by
is from PHP. PHP can't display output before using the header function; from http://php.net/manual/en/function.header.php:
Remember that header() must be called before any actual output is sent, either by normal HTML tags, blank lines in a file, or from PHP.
We recommend you to check your script to find where it's getting any output before the header.
Regards.