Obsessed with Coding

The actual files

Yes that's the part I know, but what would then go in "search.php"? That's where I get lost. That's the kind I'm looking for, I'm not building a whole search engine

I probably sound like a n00b asking this but I'm trying to make a search form for my site. I know how to make one that leads to google but not for my site.So I know what the html is on the page itself but what about the "action= " I'm not sure what do do there.Thanks in advance!