I am not sure if this is the right place to post this. If not please move the the corrert place.

Currently I am trying to work on a script similar to the one in the downloads section. However I am having a little bit of a problem with the bail() function.
Here is a snip of the code where the error is occuring:

// Treat as phone number.
$sendto = preg_replace('/[^0-9]/', '', $sendto);
$type = 'phone number';
if (strlen($sendto) != 10)
Line 72==> Bail('Phone number must be 10 digits long.');

The error is:

Fatal error: Call to undefined function: bail() in done.php on line 72

What am I doing wrong? This is also happening on the lines where the bail() function is called.