How do I pass a variable to a file that I include?

I am trying to pass a variable to a included file. I have done something like this:

$id = $_GET['id']; include('myfile.php');

And the file 'myfile.php' contains a form and a su开发者_StackOverflow社区bmit button. It's processing page is 'process.php' and in it, I have done:

$_id = var_dump($id);

// insert query

But I did not get the value of the variable, so 0 is inserted into the table.

Is there any other simpler way of doing it?

Thanks!

Functions.

Have myfile.php declare a function (e.g. myfunction), which you call in the including script.

For example:

// main.php
<?php

include('myfile.php');

process_data($_GET['id']);

// myfile.php
<?php

function process_data($id) {
    $query = 'SELECT * FROM foobar WHERE id = ' . mysql_real_escape_string($id);

    // ...
}

If you really want to pass the variable as a global, and you're referencing the global in a function or method, be sure to reference it as $GLOBALS['varname'] or to use global $varname:

function process_data() {
    $id = &$GLOBALS['id'];
    // or
    global $id;

    // ...
}

you have to pass over the value of $id inside your form in myfile.php

example:

<form action="process.php" method="post">
  <input type="hidden" name="id" value="<?= $id ?>">
  <!--- rest of your form -->
</form>

in your process.php, get the id back as following and do then your query.

$form_id = $_POST['id'];