PHP to Flash

I am able to successfully send variables to PHP with the following code.

var URL:String = “/login.php”;
var variables:URLVariables = new URLVariables();
variables.var1 = “var1”;
variables.var2 = “var2”;

var request:URLRequest = newURLRequest(URL);
request.data = variables;

sendToURL(request);

From PHP I run a script to check see if these values exist in my database. If they do then I want to echo back a string that I can bring back into flash. Can anyone please help me out with that?

An help would be greatly appreciated