ModalBox is a JavaScript technique for creating modern (Web 2.0-style) modal dialogs or even wizards (sequences of dialogs) without using conventional popups and page reloads. It’s inspired by Mac OS X modal dialogs. And yes, it may also be useful for showing bigger versions of images. :)

ModalBox is built with pure JavaScript and is based on Sam Stephenson’s excellent Prototype JavaScript Framework, script.aculo.us and valid XHTML/CSS. ModalBox uses AJAX to load content.

ModalBox Features:

• Web 2.0-ready: ModalBox uses industry-standard libraries — prototype and script.aculo.us.
• NEW! “Offline-mode”: Use dynamic- or plain-HTML without any Ajax-calls to fill out your dialog windows.
• AJAX pages loading: ModalBox uses AJAX instead of deprecated iframe for content loading. It’s also more secure — you can’t access pages which are not on your host.
• Callbacks support: You can attach your own JavaScript events after showing or hiding (and more) the ModalBox
• Automatic height adjustment: ModalBox adjust it’s height depending on your content. No more height tweaking!
• “Scrolling mode”: If your content might be long just define the height of the ModalBox and it will be switched into “scrolling mode”
• Browser and platform independent: Since most of modern browsers use popup blockers, it’s hard to find another way to create 100% browser-compatible modal dialogs.
• Multi-purpose: You can create complex wizards to guide users through the process. Image slideshows can be done too.
• Keystrokes support: Use ESC key to close ModalBox.
• Customizable Look & Feel: Use CSS to make ModalBox look like you want.
• Supports transitional effects: Slide down appearing and on-the-fly resizing.
• Lightweight: Just about 10 KB of code.
• Works in most modern browsers: Tested in IE6, IE7, Firefox 1.0, 1.5, 2.0, Safari, Camino, Opera 8 and 9.