These are options for 1.3+, for versions 1.2+ look there
Documention for fancyBox2 is available at fancyapps.com
You can pass options as key/value object to fancybox() function or modify them at the bottom of FancyBox JS file.
| Key | Default value | Description | 
|---|---|---|
| padding | 10 | Space between FancyBox wrapper and content | 
| margin | 20 | Space between viewport and FancyBox wrapper | 
| opacity | false | When true, transparency of content is changed for elastic transitions | 
| modal | false | When true, 'overlayShow' is set to 'true' and 'hideOnOverlayClick', 'hideOnContentClick', 'enableEscapeButton', 'showCloseButton' are set to 'false' | 
| cyclic | false | When true, galleries will be cyclic, allowing you to keep pressing next/back. | 
| scrolling | 'auto' | Set the overflow CSS property to create or hide scrollbars. Can be set to 'auto', 'yes', or 'no' | 
| width | 560 | Width for content types 'iframe' and 'swf'. Also set for inline content if 'autoDimensions' is set to 'false' | 
| height | 340 | Height for content types 'iframe' and 'swf'. Also set for inline content if 'autoDimensions' is set to 'false' | 
| autoScale | true | If true, FancyBox is scaled to fit in viewport | 
| autoDimensions | true | For inline and ajax views, resizes the view to the element recieves. Make sure it has dimensions otherwise this will give unexpected results | 
| centerOnScroll | false | When true, FancyBox is centered while scrolling page | 
| ajax | { } | Ajax options Note: 'error' and 'success' will be overwritten by FancyBox | 
| swf | {wmode: 'transparent'} | Params to put on the swf object | 
| hideOnOverlayClick | true | Toggle if clicking the overlay should close FancyBox | 
| hideOnContentClick | false | Toggle if clicking the content should close FancyBox | 
| overlayShow | true | Toggle overlay | 
| overlayOpacity | 0.3 | Opacity of the overlay (from 0 to 1; default - 0.3) | 
| overlayColor | '#666' | Color of the overlay | 
| titleShow | true | Toggle title | 
| titlePosition | 'outside' | The position of title. Can be set to 'outside', 'inside' or 'over' | 
| titleFormat | null | Callback to customize title area. You can set any html - custom image counter or even custom navigation | 
| transitionIn, transitionOut | 'fade' | The transition type. Can be set to 'elastic', 'fade' or 'none' | 
| speedIn, speedOut | 300 | Speed of the fade and elastic transitions, in milliseconds | 
| changeSpeed | 300 | Speed of resizing when changing gallery items, in milliseconds | 
| changeFade | 'fast' | Speed of the content fading while changing gallery items | 
| easingIn, easingOut | 'swing' | Easing used for elastic animations | 
| showCloseButton | true | Toggle close button | 
| showNavArrows | true | Toggle navigation arrows | 
| enableEscapeButton | true | Toggle if pressing Esc button closes FancyBox | 
| onStart | null | Will be called right before attempting to load the content | 
| onCancel | null | Will be called after loading is canceled | 
| onComplete | null | Will be called once the content is displayed | 
| onCleanup | null | Will be called just before closing | 
| onClosed | null | Will be called once FancyBox is closed | 
| Key | Description | 
|---|---|
| type | Forces content type. Can be set to 'image', 'ajax', 'iframe', 'swf' or 'inline' | 
| href | Forces content source | 
| title | Forces title | 
| content | Forces content (can be any html data) | 
| orig | Sets object whos position and dimensions will be used by 'elastic' transition | 
| index | Custom start index of manually created gallery (since 1.3.1) | 
FancyBox provides some function to work with it
| Method | Description | 
|---|---|
| $.fancybox.showActivity | Shows loading animation | 
| $.fancybox.hideActivity | Hides loading animation | 
| $.fancybox.next | Displays the next gallery item | 
| $.fancybox.prev | Displays the previous gallery item | 
| $.fancybox.pos | Displays item by index from gallery | 
| $.fancybox.cancel | Cancels loading content | 
| $.fancybox.close | Hides FancyBox Within an iframe use - parent.$.fancybox.close(); | 
| $.fancybox.resize | Auto-resizes FancyBox height to match height of content | 
| $.fancybox.center | Centers FancyBox in viewport |