Awesome program. I was using another designer(I love it, so I am not saying the name), that one even if said the support was there. practically really did not do what it claimed.
I downloaded the Net beans 6.7.1, I loved it the moment I started using it. It does not have a designers interface. But one thing you will learn about that program is that the helps you to learn a lot of HTML and that help you in the web development career.
Net Beans correctly point the error, even if the error display shown on the top of the error line is not that friendly, at least the tool helps you understand that there is something wrong with the code.
And top of all the programs is only 26.4MB in size. Not heavy like the total Net beans programs. This can be downloaded separately.
Net Beans also give code completion, that is it gives the php code completion help.
What more to say. That program is awesome.