Write Visitor Time Spent On Page To Delimited File

Need javascript or PHP script for a web page that will ONUNLOAD of page (exiting page) write: I.P. Address of visitor Total time in seconds on the page page name (i.e., like [login to view URL]) I want to be able to put the script on any page within my web site to track how long a visitor stays on a specific web page within my site. I want the file written to to be ready for me to import into Excel so it needs to be comma delimited and ready to go. This is a small project. A good javascript or PHP programmer will be able to do this in a very short time. But I'm always needing programming like this and more done so this may be the start of a long relationship if the work is done fast, accurately, simply and the price is fair. Must be able to use Yahoo or Skype instant messaging and must write and understand fluent English.