Any way to check input?

The best way to go about doing this would be to write a form validation rule! Its a rule that is able to be applied to whatever fields inside a form youd like. It functions very similarly to a standard rule and rules that youve already created can even be used by setting the rules behavior to Form Rule."

Heres the documentation for configuring and running validation rules: http://documentation.decisions.com/running-a-validation-rule/

Hope that helps!"