What's wrong with my code_html/css_WEB-ITnose

I just learned Html and JS and wrote the following two files. I feel that Hello world should be displayed, but actually nothing is displayed. Where did I go wrong?

Test.html content




< meta charset="utf-8">








Test.js content
function Myfunc()
{
document.writeln("Hello world");
}

Reply to discussion (solution)

Test.js content
function Myfunc()
{
alert("Hello World!');
document.writeln("Hello world" ; script type="text/javascript" src="Test.js"> Just write