in stock tracker

I need perl code (other language is fine) that runs as a cron job that checks to see if items are in stock at various retailers. My guess is you will need to parse the pages using URI and look for the site specific in stock message. There should also be a simple admin interface where I can add or delete items to be tracked (stored in Mysql database). also the results should be stored in a simple table. Examples: [login to view URL], [login to view URL], etc.