call to undefined function msg() - php

Question

i m getting an error in the php code..
Fatal error: Call to undefined function msg()
but the function is already defined in the code here
whenever i click on a login button this login script runs
<?php
mysql_select_db("elunika", $con);
$a = $_POST['em'];
$b = $_POST['pwd'];
$c = $_POST['log'];
$b = md5($b);
if (isset($c)) {
$q = mysql_query("select * from registeration where email='$a' and password='$b'");
$r = mysql_num_rows($q);
if ($r) {
$_SESSION["Authenticated"] = 1;
$_SESSION['id'] = $a;
}
else {
$_SESSION["Authenticated"] = 0;
}
if ($_SESSION["Authenticated"] === 0) {
die(msg(0, "Incorrect Information"));
}
else {
session_write_close();
echo msg(1, "profile.php");
}
function msg($status, $txt)
{
return '{"status":' . $status . ',"txt":"' . $txt . '"}';
}
}
?>

Answer 1

Only unscoped functions are defined at compile-time (prior to execution). Your msg function however is just going to be defined if the if branch (the if (isset(…)) on line 9) is entered; so it's only going to be defined at the moment where the executor reaches it.
But in your code msg() is already called before the function declaration was encountered at run-time. Moving the function declaration up (= before the msg() call) should help:
function msg ($status, $txt) {
return '{"status":'.$status.',"txt":"'.$txt.'"}';
}
if($_SESSION["Authenticated"] === 0) {
die(msg(0,"Incorrect Information"));
} else {
session_write_close();
echo msg(1,"profile.php");
}