[PHPTAL] How to use PHPTAL built in parser?

[takeshin at op.pl]

How to use PHPTAL built in parser?
There are no examples in the manual how to use it.

For example, I want to have a pre-filter, which:
- finds all tags with id attribute matching "name_number", or one tag with specified id
- adds attribute onclick="myfunction(number);"
- adds myfunction(){code...} to <script> tag in the head section

How should I do it?

What about common tasks such as form validation and pagination in PHPTAL?