How to create a search box with on-page results?

I am not sure if this is the right forum to post this question in, so my apologies.

I created a text page in Sharepoint. Lets just say it has a lot of text. Because of this, we need to make it easier for people to find information and thus we need a search box. My question is…how do I create a search box so people can get on-page results (don’t take them to a results page)? We can’t get access to the HEAD of the code. All we have to use is an XML editor to create that page.

ANyone have any ideas? Doesn’t have to be javascript…just need a solution. Thanks.