Dialog Boxes

In the Internet Explorer, you can use the showModalDialog to display modal dialog boxes (dialog boxes the user must dismiss before continuing with the browser) and showModelessDialog to display modeless dialog boxes (dialog boxes that enable the user to return to the browser before being dismissed) with showModalDialog. Here’s how to use these two methods:

window.showModalDialog(URL [, arguments] [, features]) 
window.showModelessDialog(URL [, arguments] [, features])