I can't make a screenshot when using selenium

I’m trying functional test, and saw this topic:

http://www.yiiframework.com/doc/guide/1.1/en/test.functional

the comment says that it can add a screenshot when failure, it’s cool

then I try to add these codes into mine, but doesn’t work

I don’t even see any message about screenshot when failure occur

did it really take a screenshot for me?

and what is the correct path should I set?

I’m using native Mac Lion PHP’s service, I think the screenshot just send to Site/screenshot is ok

so I set my screenshot path to: /Users/username/Sites/screenshot/

is this correct?

sorry I’m not good at path… :(

oh, I got it…

it is really path problem, I setting correct path and have correct rights to it

now it works fine…