timing a session

[binaryabraham]

If you have users complete an exam using an html form and POST results to a php script, how can you time their session? Is it better to use some java script in html or is their an easier funtion in php? I read through time() function, but not sure if I should use it.

[Weedpacket]

You can use the time() function - record the time() you serve the form (store it either against their record in the database or as a session variable), and check the time() again when you receive the POSTed data. The difference between the two will be (to within a few seconds or so for network lag) the time (measured in seconds) they spent looking at and filling out the form.