I have a JavaScript file (extension `.js`, not `.html`) containing several JavaScript functions.

I want to call one of the PHP functions in a PHP file containing only several PHP functions from within one of the JavaScript functions.

* Is that possible?
* Would I need to "include" the `.php` file containing the PHP function in the `.js` file?
* How would I do that?   
 For example, say I had a file called myLib.php containing a function called `myFunc` that takes two parameters (`param1` and `param2`). Then I have a `.js` file containing a function called `myJsFunc`. How would a call the `myFunc` (PHP) from within the `myJsFunc` (JavaScript function)? Wouldn't I need to include the PHP file somehow in the `.js` file?