75479 Simple search script

I have about 1000 pages at my website that are either .html or .rtf and I need a simple search script that will allow me to find specific documents. I want to be able to enter a keyword or a phrase into the search script and it return a listing of the top 75 pages (either .html or .rtf or both) ranked according to the number of times the provided keyword or phrase appears on the page. For example: I might enter in "faith". I want the script to search all of the .html pages and .rtf pages at my site and return a listing of the top 75 pages ranked on how many times the word "faith" appears in each of those pages, along with a link to the pages themselves. I will need you to install the script. I will also need documentation on how to install the script in case I move to a new server in the future and need to reinstall. This is for personal use and not commercial. I will not need rights to the script, nor will I resale it.