Write If Then Statement

I have an office cubicles website. On this page: [login to view URL] when the user chooses a layout, it sends the variables to the next page through the URL. The first variable is "g" for grouping or "s" for single row. The second variable is how many cubicles. Here is the URL for a grouping of 8. [login to view URL] The image on this page: [login to view URL] changes depending on the URL. I just need to prices to change depending on the URL. There is a "per cubicle" price, and a different price for the whole group. Simple If/Then statement. I just don't know how to write it.