The only thing you will need to change to use this script are the four parameters being passed into the anonymous function at the end of the script. These are the id of the input field you are converting, the minimum value the field is allowed to have in it, the maximum value, and finally the step size to move the value by each time a button is clicked.
Here's an example that allows integers between zero and ten.
If you need multiple spinners in the same page then you may replace the anonymous self executing function wrapper with a function declaration so that you can call the function multiple times (once for each spinner). The modifications to do this are shown in bold below.
This article written by Stephen Chapman, Felgall Pty Ltd.