This is actually a rather simple method to learn. Not very secure mind you, but if thats not an issue its a great way to work around other possible, harder, ways.
Basically you have your address
http://www.domain.com/index.php
Then you have your destination. Say you want to pass it the variable say_hello with the value "Hello World". This is what it would look like.
http://www.domain.com/otherpage.php?say_hello='Hello World'
Now you have sent a request to 'otherpage.php' with a variable names say_hello and a value of "Hello World". To display this message on your 'otherpage.php', you would do this:
<?=$_GET['say_hello']?>
Does this make sense? Maybe it will help you get started. Here is some starter pages to play with, just to help you get started.
Save the below page as index.php:
<?php
$message = "Hello World";
?>
<html>
<body>
<a href="otherpage.php?say_hello=<?=$message?>">Click here to Say Hello</a>
</body>
</html>
Save this next page as otherpage.php:
<html>
<body>
Your message is: <?=$_GET['say_hello']?>
</body>
</html>
