Parameters in WebPage

I want to create a "double php web page"..what i mean is that it will work as a usual web page if you call it as wallpapers.php...but at the same time i want it to work as a way of getting info..i would like to that page get parameters like the date at which the page was saw but ONLY BY SOME PERSON...so my question is how do i create my page to see if the user wrote any parameter without getting errors?

i know the function to get parameters is the $_GET['var']...but how do i do the rest?

I know you posted this about 17 days ago...

...but what are you talking about? :confused:

You could retrieve indicidual information per user by using Sessions to identify them.