169650 PHP Script

I am in need of a simple php script for my website: I need to add another product category POSTERS & SIGNS and then add another pricing facility as can be seen on the banners page. The difference here though would be the user adds a size then chooses one of the options from a drop down list: POSTERS (19m2) DISPLAY BOARD (22m2) COREX (25M2) RIGID PLASTIC (45m2) DIBOND (65m2) I have shown the m2 price alonside for the calculations This then needs to generate a price and add to the shopping cart Please take a look at the site: [login to view URL]