I'm trying to learn php and don't fully understand the basic functions, elements etc. . It would be nice to see existing stuff on site, e.g. I'd like to learn how to display in my nav bar what page I'm on by turning the link in my nav bar a different colour or maybe display an image. I know a website that does this and like to see how the effect is achieved. I have firebug and web developer toolbar in firefox, could I use these? Also how do you validate scripts with the developer toolbar?