How to receive data from my server database to a variable in my Arduino?
After you send the GET request, you read the response to fill the char result [20] variable you declared:

int i=0;
...
if (client.connect(server, port))
{
  client.print("GET /locator.php?");
  ...
  Serial.println("\nCOMPLETE!\n");

  // Read response from server
  i=0;
  while (client.available())
  {
    result[i] = client.read();
    Serial.print(result[i]);
    i++;
  }

  client.stop(); // disconnect
}


This is an example, result will contain the text output by locator.php. You will need to tweak this code to apply to your case. The above code has no error checking of any kind. Also, you should perform a check and only make the web call one time. 

In locator.php you should replace echo "&lt;br/&gt;"; with echo "\n";. And for good measure, make sure there is no white space before &lt;?, and remove the trailing ?&gt;.