How to Create a Popup Window, Such as a Login Form

First, put the login form inside a div, including fields such as username and password, and set display to none in its CSS.

Then, on your frontend page, such as index.html or index.jsp, add a login button and bind its onclick event to a function defined in a .js file. This function controls whether the div containing the login form is shown or hidden. It is hidden by default. When you click the login button, the function calls $(".div的class名").show() to display it, creating a popup effect.