Written
Sometimes you need to check that a form input has a text string of a specific length, or is not longer or shorter that some specific values.
You can do this very simply by adding an entry to the Field Class box input element:
validate['length[min,max]']
Where 'min' and 'max' are the minimum and maximum length allowed. For example:
validate['length[5,8]']
To set an exact length, set 'min' to the length and set 'max' to -1. For example:
validate['length[12,-1]']
