Php processor and return window

I am just learning PhP. When I was teaching myself Lingo (Macromedia Director's programming language) I found an object called the MESSAGE window quite helpful. This window allowed you to execute little snippets of code and get the results without having to execute your entire script. For instance, you could create a variable and give it a value then run an if/then statement or loop on it and quickly see the results. This is quite convenient when you're learning the language because you can test your syntax line-by-line instead of having the whole script fail and not knowing exactly where the error occurred. Does anyone know about anything like this for PhP? Thanx, -- Robb Kerr Digital IGUANA Helping Digital Artists Achieve their Dreams http://www.digitaliguana.com http://www.cancerreallysucks.org