try this:
$(".target").fancybox({
'zoomSpeedIn':500,
'zoomSpeedOut':300,
'easingIn': 'easeOutCubic',
'easingOut': 'easeInBack',
'overlayOpacity': 0.5,
'frameHeight': 499,
'frameWidth': 345,
'imageScale': true,
'overlayShow': true,
'callbackOnStart':function(){$(".target").hide();},
'callbackOnClose':function(){$(".target").show();}
});
you could make a reference to any element with a different class (or
ID) on callbackOnStart and callbackOnClose, i.e. you can hide/show a
specific text or image within your screen
<h1 class='disappear'>I will disappear if you open fancy box</h1>
then
$(".target").fancybox({ //this will open in fancybox
'callbackOnStart':function(){$(".disappear").hide();},
'callbackOnClose':function(){$(".disappear").show();}
});