I have some Ajax code in a Zen Cart that is designed to add letters to a shirt. You should be able to go through and pick the letters and color and pattern that you want and have it added to the shirt. The letter should only have a color or a pattern selectable, not both.
1) Go to <[url removed, login to view]> and click "T-shirts $20" image
2) Click on a color swatch and click "Continue"
3) Select a letter from the first dropdown (like "Alpha") and click "Continue"
4) Click on any image in "Foreground Color" and "Foreground Pattern" then click "Add Product" in the upper-right.
You will see both the Foreground Solid and Foreground Pattern in the cart. There should only be one. Only the last thing you pick should be in the cart. So if you click a color, then a pattern, only the pattern should display and vice versa.