[php]how to track the survey progress in php?

how to track the survey progress in php? I want a wordpress content plugin with tracking the surveys, knowing if the survey is done.
what info should i know? A survey outside the site is ok?
Can anyone help me? Or is it hard to realize?
Thanks in advance.

Are you wanting an off-the-shelf survey script, or are you writing it yourself?

Not sure right now bout how to track it, but if you want to track from an external website you have to have a way of output from that site to your server (website), and so to track the progress, which i find is not the case in many surveys like surveymonkey etc. So yes survey outside your site is hard.