Flash can't read php var when acquired from GET

programming
1

Ok, my problem is I have a PHP file that sends variables to another PHP file via $_GET which contains a flash bit that must read these variables in order to work.
The funny bit is if I manually declare the variable like so

$su=“smith”;
echo “test=$su&”;

it works, but

$su=$_GET[‘surname’];
echo “test=$su&”;

won’t work.

Thanks in advance!
Leo