# Cannot modify header information-headers already sent!

**URL:** <https://forum.kirupa.com/t/cannot-modify-header-information-headers-already-sent/308740>\
**Category:** programming\
**Created:** [April 29, 2010, 5:52am UTC](https://forum.kirupa.com/t/cannot-modify-header-information-headers-already-sent/308740 "2010-04-29T05:52:53Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![NovemberRain](https://avatars.discourse-cdn.com/v4/letter/n/73ab20/32.png) [@NovemberRain](https://forum.kirupa.com/u/NovemberRain)\
**Post date:** [April 29, 2010, 5:52am UTC](https://forum.kirupa.com/t/cannot-modify-header-information-headers-already-sent/308740/1 "2010-04-29T05:52:53Z")

</div>

Hi,

I’ve a common header for my php script. That includes session checking and manipulate the links based on the user logged in or not. This header is used for all the pages. The problem is redirection for many pages not working. It shows an error.

Cannot modify header information - headers already sent

how to resolve this issue.

thanks in advance.