how to include a javascript at the end of my page through a plugin

Hi all,

I’m pretty new to WordPress but I’m learning fast.

I wrote a plugin, and I’m calling its functions from a custom template page /testpage/.

I need to register a function that echoes a javascript to be included at the very end of the html page, but I don’t know how to do it.

To include css files in the head I did something like this:

add_filter('wp_head','myplugin_css');
function myplugin_css()
{
echo '<link ..........';
}

What is the equivalent I may use to print ‘<script ….’ at the very end of the page before </body> tag?

Thanks in advance for any help.