Wut?
You running a browser via file:// or http:// protocols? You have to access it via http:// protocol and the server must be configured to serve as PHP code. That is a configuration issue on your host assuming you're not talking about a local machine.
//Please don't use this for your form processing:
if (isset($_POST['submit']))
//Internet explorer has a bug and does not always send the submit value.
You cannot open a php script and have it parse. You have to use a webserver or an executable to parse it and return the results (ie: your browser using http protocol for example).
As Fou says, you will need a webserver to run it on and then access it via http using a browser. You can do this either by uploading it to your website that you already have OR by installing a server system such as wamp, xamp, uniformserver on your own windows system and then using the http://localhost address.
//Please don't use this for your form processing:
if (isset($_POST['submit']))
//Internet explorer has a bug and does not always send the submit value.
//Please don't use this for your form processing:
if (isset($_POST['submit']))
//Internet explorer has a bug and does not always send the submit value.