Cookie Problems

[BladeMetal]

Ive tries to set a cookie like below:
<?php setcookie("cookiename",$managerid,time()+3600,"/");?>

However i keep getting this error when i upload it:

Warning: Cannot modify header information - headers already sent by (output started at /var/www/html/teamtactics.php:7) in /var/www/html/teamtactics.php on line 59

what causes this and how can i fix it

my code is below:

<?php
$managerid = $POST["managerid"];
$password = md5($POST["password"]);

$link = mysql_connect("localhost","username","password");
@mysql_select_db("databasename",$link);
$sql = "SELECT * FROM teaminfo WHERE teamid='$managerid'";
$result = mysql_query($sql);

$checkpassword = mysql_result($result,0,'password');
echo $checkpassword;
if ($checkpassword == $password) {
	setcookie("cookiename",$managerid,time()+3600,"/");  ****THIS LINE CAUSES THE ERROR****
	echo "<meta http-equiv='refresh' content='0,http://website.com/teamtactics.php'>";
} else {
	echo "Sorry, the password you typed is incorrect for the Manager ID you entered (".$managerid.").  Will return to the home page in 10 seconds";
	echo "<meta http-equiv='refresh' content='10,http://website.com/index.html'>";
	}

?>

[Sayian]

You must send ALL Header information before any BODY ( html ) information is sent , Once the headers are sent , you cannot modify them.

Please your cookie code before ANY html and it will work fine ..

[palanisamy]

In your code, you echo the password before setting the cookie. When set the there is no echo statement not there in your code.

Remove the echo $checkpassword; in your code it will work fine.

Regards,
Palanisamy

[Weedpacket]

Removing the echo $checkpassword is necessary, of course (I can see that it's there for debugging). But as the others have said, you can't be generating any output before you use header functions like header(), setcookie() and so on; the headers have to go first, so you need to get all of those out of the way before you get on to outputting anything else. Start looking at what is being output by line 7 of your code. That's the first point of failure.