我知道要使 header(Location) 工作，必须先发送没有输出。问题是我已经检查了很多次代码，但找不到实际作为输出发送的内容，从而阻止了我的标头（位置）工作。
任何人都可以发现错误吗？
<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>
