如何将jquery脚本限制为容器div的大小

I have created a gallery and buttons to control the gallery as well. I am a newbie to jquery and used a small script to change the margin by a fixed amount on a div container. The script works great but it extends past the top and bottom of the div contents. I would set a specific size to the div, but the idea is to use this on multiple pages with varying amounts of content. How do I restrict the the button function to not expand past the content inside the div?I have created a gallery and buttons to control