If you want to embed dynamic code - be it php, forms or javascript - on a page, then you should use the DynPages plugin.

Download the plugin and unzip it to the plugins directory of your GetSimple installation.

You use place holders on your page to include components, e.g. to include a site map:

Here is the map of this site:
{% sitemap %}

(If the place holder is the only text within the paragraph, the paragraph is removed, before including the component)

Then you need to define the component sitemap, e.g.

<ul><?php get_i18n_navigation('index',0,99,I18N_SHOW_PAGES); ?></ul>

This will display a sitemap on the page (uses the I18N Plugin).

You can also pass parameters to the component, which the component can then access via the global variable $args.

For example create a component "sitemap", which takes as parameters the depth of the site map:

<ul><?php
  global $args;  
  get_i18n_navigation('index',0,$args[0],I18N_SHOW_PAGES); 
?></ul>

To use it, include a place holder with its name and a parameter on your page:

Here are the first three levels of this site:

{% sitemap 3 %}