header(Location) not working [duplicate] - php

Question

This question already has answers here:
How to fix "Headers already sent" error in PHP
(11 answers)
Closed 9 years ago.
I'm aware of the fact that for header(Location) to work, no output must be sent before. The problem is that I've checked my code so many times but can't find what is actually being sent as output, thus preventing my header(Location) from working.
Can anyone spot the error?
<div id="content">
<h2>Lägg till</h2>
<p>Fyll i fälten och klicka på Lägg till för att skapa en ny kontakt i listan.</p>
<?php
$editid = $_GET['contact_id'];
$query = "SELECT *, Persons.p_id FROM Persons INNER JOIN Pictures ON (Pictures.p_id = Persons.p_id) WHERE Persons.p_id = " . $editid;
$result = mysql_query($query);
while ($row = mysql_fetch_array($result)) {
$name = $row['name'];
$address = $row['address'];
$birthday = $row['birthday'];
$picture = $row['source'];
$p_id = $row['p_id'];
}
?>
<form action="" id="addressForm" method="post">
<ul>
<li><label for="name"><strong>Namn</strong></label><input type="text" name="name" id="name"/></li>
<li><label for="address"><strong>Adress</strong></label><input type="text" name="address" id="address"/></li>
<li><label for="year"><strong>Födelsedag</strong></label>
<select id="year" name="year">
<option value="2013">2013</option>
<option value="2012">2012</option>
<option value="2011">2011</option>
<option value="2010">2010</option>
<option value="2009">2009</option>
<option value="2008">2008</option>
<option value="2007">2007</option>
<option value="2006">2006</option>
<option value="2005">2005</option>
<option value="2004">2004</option>
<option value="2003">2003</option>
<option value="2002">2002</option>
<option value="2001">2001</option>
<option value="2000">2000</option>
<option value="1999">1999</option>
<option value="1998">1998</option>
<option value="1997">1997</option>
<option value="1996">1996</option>
<option value="1995">1995</option>
<option value="1994">1994</option>
<option value="1993">1993</option>
<option value="1992">1992</option>
<option value="1991">1991</option>
<option value="1990">1990</option>
</select>
<select name="month">
<option value='1'>1</option>
<option value='2'>2</option>
<option value='3'>3</option>
<option value='4'>4</option>
<option value='5'>5</option>
<option value='6'>6</option>
<option value='7'>7</option>
<option value='8'>8</option>
<option value='9'>9</option>
<option value='10'>10</option>
<option value='11'>11</option>
<option value='12'>12</option>
</select>
<select name="day">
<option value='1'>1</option>
<option value='2'>2</option>
<option value='3'>3</option>
<option value='4'>4</option>
<option value='5'>5</option>
<option value='6'>6</option>
<option value='7'>7</option>
<option value='8'>8</option>
<option value='9'>9</option>
<option value='10'>10</option>
<option value='11'>11</option>
<option value='12'>12</option>
<option value='13'>13</option>
<option value='14'>14</option>
<option value='15'>15</option>
<option value='16'>16</option>
<option value='17'>17</option>
<option value='18'>18</option>
<option value='19'>19</option>
<option value='20'>20</option>
<option value='21'>21</option>
<option value='22'>22</option>
<option value='23'>23</option>
<option value='24'>24</option>
<option value='25'>25</option>
<option value='26'>26</option>
<option value='27'>27</option>
<option value='28'>28</option>
<option value='29'>29</option>
<option value='30'>30</option>
<option value='31'>31</option>
</select>
</li>
<li><label for="picture"><strong>Bild (URL)</strong></label><input type="text" name="picture" id="picture"/></li>
<li><input type="submit" id="submit" name="submit" value="Lägg till"/></li>
</ul>
</form>
<?php
if(isset ($_POST['submit']))
{
$editname = mysql_real_escape_string(htmlspecialchars($_POST['name']));
$editaddress = mysql_real_escape_string(htmlspecialchars($_POST['address']));
$editpicture = mysql_real_escape_string(htmlspecialchars($_POST['picture']));
$year = $_POST['year'];
$month = $_POST['month'];
$day = $_POST['day'];
if ($month < 10)
{
$month = "0$month";
}
if ($day < 10)
{
$day = "0$day";
}
$editbirthday = $year . "-" . $month . "-" . $day;
if (!empty($name) && !empty($address)){
$update = "UPDATE Persons SET name = '$editname', address = '$editaddress', birthday = '$editbirthday' WHERE p_id = '$editid'";
$result = mysql_query($update);
$query = "SELECT * FROM Persons WHERE p_id = '$editid' LIMIT 1";
$result = mysql_query($query);
while ($row = mysql_fetch_array($result)) {
$p_id = $row['p_id'];
$update = "UPDATE Pictures SET source = '$editpicture' WHERE p_id = '$editid'";
$result = mysql_query($update);
header('Location: index.php');
}
}
}
?>
</div>

Answer 1

Remember that an output could be:
Whitespace before <?php or after ?>
UTF-8 Byte Order Mark
Error messages or notices
print, echo
Raw <html> areas before <?php code.
So you're hitting the final point of this list...

Answer 2

You must put the header ABOVE any HTML output. You can just put it at the top of your document in this case. So just put all the PHP at the top.
Put the whole if statement from the following, to the top of the PHP file. I don't think this will cause any issues.
if(isset ($_POST['submit']))
I hope this helps

Answer 3

You already have output. Headers MUST be set before any output is sent.
"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."
Refer to the documentation about it. Hope this helps.

Answer 4

no output
no whitespace
save file without BOM