Old browsers do not support html5 however using the published .js functionality will enable replacement for the html5 tags that is not supported by older browsers. Enter the following code in the <head> section of your webpage
<!DOCTYPE HTML> <html> <head> <!--[if lt IE 9]> <script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script> <![endif]--> </head> <body> </body> </html>
If for some reason this does not satisfy your needs, you can check up modernizr
Go to http://www.modernizr.com/ to download this library.