Problem with php and flash interaction

My flash works fine when I run it in the flash player, but does not work in the web browser… The yourName field is always undefined when I run it in the browser.
this is my AS

// for select query
var select_lv:LoadVars = new LoadVars();

// create a string to show where to access the PHP script
var filepath:String;

if (_url.indexOf(“http”) != 0) filepath = “http://localhost/tutorial/”;
else filepath = “…/test/”;

select_lv.onLoad = function(ok:Boolean) {
yourName=this[“nickname”];
}

select_lv.sendAndLoad(filepath + “getscores.php”, select_lv, “GET”);

and my php is just

<?php
echo ‘&nickname=bob&’;
?>

When I tried to preview the flash file locally in firefox I get a pop up saying:

adobe flash player has stopped a potentially unsafe operation.

The following local application on your computer or network:

blabla.swf

is trying to communicate with this Internet-enabled location:

my ip address

to let this application communicate with the Internet, click settings.

You must restart the application after changing the settings.

I am going to assume facebook is probably trying to block the same action

Can you guys send me a link or tutorial as to how I can get flash to interact with the variables in php?