Can't get variables from other php file - php

Question

I have this code in index.php
<?php
include "ch.php";
?>
ch.php
<?php
if (isset($_POST['Murad'])) {
header("Location: Main.php");
$firstname=$_POST['firstname'];
$lastname=$_POST['lastname'];
$userName=$_POST['username'];
$password=$_POST['pwd1'];
$userName = stripslashes($userName);
$password = stripslashes($password);
$userName = mysql_real_escape_string($userName);
$password = mysql_real_escape_string($password);
$email=$_POST['email'];
$mysql_hostname = "localhost";
$mysql_user = "root";
$mysql_password = "123";
$mysql_databse = "websiteusers";
$prefix = "";
$bd = mysql_connect($mysql_hostname, $mysql_user, $mysql_password) or die("Could not connect database");
$sql = "
INSERT INTO websiteusers
(fullname,lastname,userName,email,pass)
VALUES ( '$firstname', '$lastname','$userName', '$email','$password')
";
mysql_select_db('websiteusers');
$retval = mysql_query( $sql );
if (! $retval ) {
die('Could not enter data: ' . mysql_error());
return false;
} else {
echo "Entered data successfully\n";
}
$usernamecheck=mysql_query("
SELECT `userName` FROM `websiteusers`
WHERE userName='$userName'
");
if (mysql_num_rows($usernamecheck)>=1) {
echo $userName." is already taken";
return false;
}
}
?>
And
Main.PHP
<?php
include 'ch.php';
?>
And
<?php
echo $firstname=$_POST['firstname'];
?>
But it is not working. It worked before I put action in form instead of header but it didn't insert user in database now it inserts but it is not showing variables. Is there anyway to fix this?

Answer 1

1) Do not use mysql_ functions, it's deprecated and will be removed at PHP 7 stable release, choose between mysqli_ or PDO.
2) Don't open and close your php interpreter multiple times with no apparent reason. If your code is pure PHP, a standard is to never close it.
3) There should be nothing else for PHP or HTML to be processed/displayed after using header("Location: ...") function. It's the last thing you do at the script when you use it.