Enter the CSS property ‘overflow’.

* overflow: auto – This will create a scrollbar – horizontal, vertical or both only if the content in the block requires it. For practical web development, this is probably the most useful approach to creating a scrollbar.
* overflow: scroll – This will will insert horizontal and vertical scrollbars. They will become active only if the content requires it.
* overflow: visible – This will cause the content of the block to expand outside of it and be visible at the same time.
* overflow: hidden – This forces the block to only show content that fits in the block. Other content will be clipped and not visible. There will be no scrollbars.

CSS code:

in the add DIV layer with overflow contents
This is a scrolling are created with the CSS property overflow.

Best Practices for Speeding Up Your Web Site

* Minimize HTTP Requests
* Use a Content Delivery Network
* Add an Expires or a Cache-Control Header
* Gzip Components
* Put Stylesheets at the Top
* Put Scripts at the Bottom
* Avoid CSS Expressions
* Make JavaScript and CSS External
* Reduce DNS Lookups
* Minify JavaScript and CSS
* Avoid Redirects
* Remove Duplicate Scripts
* Configure ETags
* Make Ajax Cacheable
* Flush the Buffer Early
* Use GET for AJAX Requests
* Post-load Components
* Preload Components
* Reduce the Number of DOM Elements
* Split Components Across Domains
* Minimize the Number of iframes
* No 404s
* Reduce Cookie Size
* Use Cookie-free Domains for Components
* Minimize DOM Access
* Develop Smart Event Handlers
* Choose over @import
* Avoid Filters
* Optimize Images
* Optimize CSS Sprites
* Don’t Scale Images in HTML
* Make favicon.ico Small and Cacheable
* Keep Components under 25K
* Pack Components into a Multipart Document