$(document).ready(function() { 
/* This is basic - uses default settings */ 
$("a#single_image").fancybox({ 'zoomSpeedIn': 300, 'zoomSpeedOut': 300 });
$("a.single_image").fancybox({ 'zoomSpeedIn': 300, 'zoomSpeedOut': 300, 'hideOnContentClick': false });

/* Using custom settings */ 

$("a#inline").fancybox({ 'hideOnContentClick': false }); 
$("a.group").fancybox({ 'zoomSpeedIn': 300, 'zoomSpeedOut': 300 }); 

});