404 error help

[dlf1987]

I went in plesk and told it where my custom 404 page that looks like the rest of my site is. Works fine.

 

On my 404 page i have a mysql insert that records data about the 404 page. But im having trouble finding the exact pages that are causing the 404's, ive tried using $_SERVER['HTTP_REFERER'], but that doesn't give me the correct page, ive tried getting the url of the 404 page, but that doesnt tell me what url caused the 404 error.

 

thanks