Question: I had made a java program in which it is supposed to take input from a user in a GUI frame and store in a .dat file in row and columns. The problem is with this particular code as it is not giving the desired results. the user should be able to enter only numbers between 20 to 30 using a keylistener. the input should not accept any number that is out of this range, i.e, 19 or 31. Eclipse is throwing an error 'invalid character constant'. Is there any way out?

```
// input validation that restricts user to enter specific number range between 20 and 30

txDeposit.addKeyListener(new KeyAdapter() {
    public void keyTyped(KeyEvent ke) {
        char c = ke.getKeyChar();
        if(!(ke.getKeyChar() >= '20' && ke.getKeyChar() <= '30')) {
            getToolkit().beep();
            ke.consume();
        }
    }
});

```

Answer: 
Your app.yaml file is for routing requests from incoming URLs to the initial script you want to use to process the request.

You don't need to add routings for each and every \*.php file that you want to include from one script to another.

For example, look at the [app.yaml](https://developers.google.com/appengine/articles/wordpress) example for running wordpress. It just has the URLs that clients will access, but not all of the php scripts used by wordpress.
The error 500 was thrown basically because Google App Engine for php doesn't support CURL extension used in the Facebook php SDK. Nothing related to app.yaml includes.
I forked the official fb sdk git and I'm patching a solution right now.