Warning: Cannot modify header informati on - headers already sent
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/1912029/warning-cannot-modify-header-information-headers-already-sent-by-error">&ldquo;Warning: Cannot modify header information - headers already sent by&rdquo; error</a><br>
  <a href="http://stackoverflow.com/questions/8028957/headers-already-sent-by-php">Headers already sent by PHP</a>  </p>
</blockquote>



<p>i'm having a warning it states:</p>

<pre><code>Warning: Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\projects\wesm\intranet\plugins\company_calendar\calendarpdf.php:90) in C:\xampp\htdocs\projects\wesm\intranet\plugins\company_calendar\mpdf\mpdf.php on line 7236

Warning: Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\projects\wesm\intranet\plugins\company_calendar\calendarpdf.php:90) in C:\xampp\htdocs\projects\wesm\intranet\plugins\company_calendar\mpdf\mpdf.php on line 1827
mPDF error: Some data has already been output to browser, can't send PDF file
</code></pre>

<p>can you give me some advice to get rid of those warnings..</p>

<p>Here are some of my codes:</p>

<pre><code>&lt;?php

include "admin/include/connect.php";
include "include/calendarFunction.php";
$function   = new calendarFunction();
$cMonth     = $_GET['cMonth'];
$cYear      = $_GET['cYear'];

$htmldata = $function-&gt;calendarPDF($cMonth, $cYear);

$currString = $htmldata;
$stringtoDelete  = '';
$newCurrString = str_replace($stringtoDelete, " ", $currString);
$html = $newCurrString ;
include("mpdf/mpdf.php");

$mpdf=new mPDF(); 
$mpdf-&gt;AddPage('L');

$mpdf-&gt;WriteHTML($html);
$mpdf-&gt;Output('calendar.pdf','I');
exit;

?&gt;
</code></pre>
