Comparison Functionality

We would like to add a comparison functionality to our website, similar to this [login to view URL] However these are our requirements. We do not want the comparison on a seperate page. * We are running osCommerce 2.3.1 * All coding must be in line with osCommerce 2.3.1 standards. If you have never worked with osCommerce this is probably not a job for you * We are running mySQL database with extra tables to hold product features for each product, relevant to the category it appears in * There should be a narrow information box (Compare Box) just below the header which when empty will contain the words "Select products to compare by clicking the Compare button next to your selected products" * Every product page need a "Compare" button * Product listing pages (search, categories, new products module, etc - basically wherever products appear) need a "Compare" button next to each product * When customer clicks "Compare" button a small image and the name of the product will appear in the Compare Box (using Ajax) - this will probably enlarge the box vertically - and the words "Select at least one other product from the <php insert category that first product is from here> Category to compare" * When customer selects another product to compare it will also appear in the Compare Box and instead of the text "Select at least one other product from the <php insert category that first product is from here> Category to compare" appearing, a "Compare these products" button will appear. * If customer attempts to add a product to the compare box from a different category to any other items in the Compare Box, a warning will appear (which dims the main page and shows up in a div box) which will say "You can only compare items from the same category" * No more than 4 items should be able to be compared, if customer attempts to add more a similar warning will appear. * There should be a remove button for each item in the Compare Box * When there are two or more items in the Compare Box and the "Compare these products" button is clicked, the page will be dimmed and a box will appear on the page with the comparison details (similar to this compare table on this page [login to view URL]), however all we will need is Manufacturer Name Product Image Product Name (language specific) Specification Headings - (there may be several) (language specific) Category Features under each of the Specification headings (language specific) These are all drawn from the database! Information will need to be in the customers selected language. * There should be functionality for the customer to share the comparison - in which case a new page will need to be made to display the comparison, the details of the comparison (i.e. product numbers) will be written to the database and then the customer will be given a unique URL to post elsewhere (blogs, twitter, forums, facebook etc) which when clicked will return to our site to the relevant comparison page. * If customer is signed in the comparison should be able to be saved to their customer id (needs new table to hold comparisons and new page to display comparisons when they are signed in) * If customer is not signed in there should be a button "Save this" added to comparison, when clicked it will take them to sign in and once they have signed in save it to their account id * All text for Compare Box and Warnings will be as defines as this is a multi language site. * A basic design for boxes, warnings, etc is fine as we can tweak that ourselves, however functionality is paramount. Note: Compare information in the database is already in the relevant language. Any questions, please let me know.