How to print an external page

I am trying to print an external source by clicking on a button. I found multiple scripts on the internet but none of them are working.

So my question is, how can I print a specific page by clicking on a button?

Now I have:

<iframe id="frame" src="./test.php"></iframe>

<button onclick="printOtherPage()">Print</button>
<script type="text/javascript">
  function printOtherPage() {
  document.getElementById('frame').contentWindow.window.print();
</script>

Answer

To do this:

1. Create a new iframe element.
2. Set the src of the iframe to the page you want to print.
3. In javascript, contentWindow is used to retrieve the document in iframe.

So use this code to print:

document.getElementById('frame').contentWindow.window.print();

Correct me if I am wrong.