Inventory page refresher and price grabber III

Here is our project: We need a software to refresh a web page ([login to view URL];cs=22&l=en&s=dfh) with a adjustable frequency on a Win XP Home system. Follow my instruction you will get my requirement: Go to web page ([login to view URL];cs=22&l=en&s=dfh) by using Internet Explore. On that page, MANUALLY select “Demension Desktops” in dropdown menu “Stockrooms” and “Demension XPS 400” in dropdown menu “Model”. Then click the “Price” button; items will be sorted by price. Note: all above operations can be done manually. Our operator will do those. After that, the required software will take over. User should be allowed to input a price, for example $600. This software should refresh this page at least 5 times per second. If software find an item (or items) is below $600. This software should click “select” box in column of “Add to Cart”, and then click “Add/View Cart” button. Then, the software should stop automatically and give out a significant sound alert. Keep this in mind, when software is refreshing page, operator should has chance to see that web page. We will run this software on Windows XP Home version. Please do those steps yourself before bid. Refresh that page by clicking “F5”button. You will know what software should do.