Is Numeric validation
This ascertains if the submitted data is a numeric value.
- Error message - The message to display next to the element if the validation fails. This text should explain why the validation failed and what steps the user should take to remedy the error.
- Condition - A PHP expression which if returns false, means that the validation is not run. See here for more information.
- Allow empty - If set to yes the validation will allow an empty value, if set to no then an empty value will cause the validation to fail