How to pass variables from one php page to another without form?

Question

I want to know how to pass a variable from one page to another in PHP without any form.

What I want to achieve is this:

1. The user clicks on a link

Answer 1

check to make sure the variable is set. Then clean it before using it:

isset($_GET['var'])?$var=mysql_escape_string($_GET['var']):$var='SomeDefaualtValue';

Otherwise, assign it a default value ($var='' is fine) to avoid the error you mentioned.