Plain JavaScript (hello world) developmnent in WS?

Hello all,

I've just installed WS with the objective of developing a simple DOM manipulation JavaScript file. If I understood correctly, WS supports plain JS, but from all the search I've made here (and outside) this forum, I've just found how to set up WS to work with Node.js.

So, my beginner question is as simple as this: how can I configure/set up WS to run a simple hello world JavaScript example?

<script>
    alert( 'Hello, world!' );
</script>

The error I'm getting is (I'm on Windows 7):

"C:\Program Files\JetBrains\WebStorm 2017.3.2\bin\runnerw.exe" "C:\Program Files\nodejs\node.exe" C:\Users\Joao\WebstormProjects\xml_insert_html\insert.js
C:\Users\Joao\WebstormProjects\xml_insert_html\insert.js:2
 alert( 'Hello, world!' );
 ^

ReferenceError: alert is not defined
 at Object.<anonymous> (C:\Users\Joao\WebstormProjects\xml_insert_html\insert.js:2:5)
 at Module._compile (module.js:643:30)
 at Object.Module._extensions..js (module.js:654:10)
 at Module.load (module.js:556:32)
 at tryModuleLoad (module.js:499:12)
 at Function.Module._load (module.js:491:3)
 at Function.Module.runMain (module.js:684:10)
 at startup (bootstrap_node.js:187:16)
 at bootstrap_node.js:608:3

Process finished with exit code 1