Javascript - Show a pop-up window onChange

I want to show a html pop-up window, onChange from an input text开发者_如何学JAVA to another.

How can I do that ?

Thanks a lot.

Here's a jQuery solution:

HTML

<form ...>
   <input type="text" id="first"/>
   <input type="text" id="second"/>
</form>

JavaScript

$(function ()
{
    $('#first').blur(function ()
    {
        alert('show the popup here');
    });
});

Basic demo.

window.open() demo. Disclaimer: this behavior is extremely annoying to users.