javascript - How to implement a pop-up window when entering the homepage of a website?

As soon as you enter, a prompt pops up in the middle

Reply content:

As soon as you enter, a prompt pops up in the middle

I think it should be the window.onload event

alert("The content you want to pop up");

(function(){alert('');})()

Alert can be solved, but the experience is not good.

Recommend a lightweight jQuery pop-up component
http://layer.layui.com/

It depends on how you want to implement it. The most common way is to give an alert prompt, or make a spring layer yourself, or use a spring layer library~