Calculate square meter price

[OrangeJuice1]

Hi

I  need the option to sell products in square meter, though some products will be sold as normal price. The square meter option needs to provide the user two dropdowns, length and width on the product page, once selected the price should be calculated and displayed. Then the user can add to cart.

After doing some research I found javascript code is needed in template/catalog/product/view/options.phtml file for the frontend price. And observers are required (which ensure correct cart price is added on server side) but I don't know where to add them.

Could someone confirm please and assist?

[FmeAddons]

This can be done by using an extension, which is a easy way to do that.

Here is an extension that let customers to input the length and the width of the product in meter, Once the user enter the measurement this extension automatically calculates the price and let customers to add the same on cart and checkout.

For more details - http://www.magentocommerce.com/magento-connect/dynamic-square-foot-pricing-calculator.html