Code:
$("#code_samples").click(function() {
$("#main_centerbox").animate({
left:'0px',
top:'0px',
height:'auto',
width:'90%',
overflow:'auto'
});
$(".maintext").hide();
$("#code_samplesdisplay").fadeIn("slow");
});
});
Your height is set to Auto. Everywhere else it's set to 100%. Also, check out that width, it's 90%, everywhere else, except one, has 100% as well. Change that and I think you'll get the result you were looking for.