353692 Modify PHP on current site

Hi, I have an existing website at: [login to view URL] This website is a customised online shop selling photos and related artifacts. The website is coded in PHP. Currently there are some problems with some functions that I urgently need rectification, namely: 1) Shopping cart The shopping cart allows for quantity discount as well as coupon discount. There are some calculation errors that we can't seem to resolve. Could consider scraping the current code that calculates the shopping cart and replace with a new one. 2) Transaction details Currently, the details of the shopping cart is not transferred/saved into the database correctly. Hence when customer logged into see their purchase history, the transaction details are incorrect. Need fixing. We have an urgent need for this 2 functions to be fixed within the next 2 days, so please bid only if you are currently free and can start immediately, and not a few days later. There are some other non-critical amendments that we wish to make to the site as well, after the above 2 changes are done. These non-critical amendments can be discussed later as add-on to the project, or separately. For more details of the project (if the above is not clear enough), please PM me. Thanks. Regards, Alva