If you need an add handler for PHP please use the following:
#PHP5
AddHandler application/x-httpd-php5 .html .htm
#PHP4
AddHandler application/x-httpd-php4 .html .htm
That is if you need to parse .html files or any other extension as PHP you can place that in your .htaccess file.
Note: this script only work for old server that support both PHP4 and PHP5