make scrolling content in blogger

In blog ,sometime our content is so long ,and it will break the proportion of our layout . But we can't divide post into shorter posts . What should we do now ? we can add a textbox for content and a scrollbar in the right side for sliding up and down . But we can do more than that .Let's see the demo here .When your mouse is on button "up" ,the content is scrolled up ,and when mouse is on "down