Text input box that times the total by the number entered

I originally wanted to have was multiple quantity boxes so some one could order 30 shirts and select the different sizes at the same time, like 10 med. 10 large. 10 enlarge. But I look and posted the question with no response, so maybe I can do the same thing with a text input box. The problem is right now they go through this process designing the shirt and can only order 1 size at a time, so they have to go through the process re-enter the info for each size they want. So at the bottom I was thinking of a text input box for S M L XL etc and whatever number they enter it times the total by that number. Right now I know how to add a specific amount of money to the total, just wondering if there is a text input box that works like a quantity box as far as increasing the total price by the number enter.

Thanks

Brad

Sorry Brad, by definition a text box would collect 'text' from your visitors and the only way to turn this into numbers would be to make programming changes to turn this text into numerical data with which you can perform arithmetic calculations.

On of the joys of Open Source software, and Zen Cart in particular, is that the source code is available to allow you to do this, but in the case, to carry the changes accurately through the checkout, would require a high degree of Zen Cart knowledge and programming skill.