How do i test my PHP application or website?

Hi

I’ve been involved in developing php based websites and php web applications and all i do is have a bit of unit testing before releasing them…

My Unit testing doesn’t have a formal procedure and i just test by going through all pages and links and data submission to check whether they are actually behaving what i supposed to…

And in some cases of web application i write manual txt test cases where i note the situation and the scenario to be recreated and the task to be done and i wrote the expected results … If they meet the expected results i mark them as passed or else i just go back to code to check manually in every part of code where the error lies…

What i need to know is what is the best method to test website and php applications and what are the best tools ???

it sounds like you’re not actually unit testing in the correct sense of the word. Unit testing involves writing an accompanying set of classes which test each unit in your app.
http://www.phpunit.de/manual/current/en/automating-tests.html
The hard part is writing tests - and it’s often better if you’re not the developer responsible for that part.
Then you can use something like Selenium to run some application behaviour tests (which sounds like the closest match to the kind of testing you’re doing)