Quite some time ago, I started wondering about a nice way to do server side form validation. After pondering about what sort of features I wanted, I started to write them down on paper.

These were the features that I came up with:

• Visual clues that something is in error (background colour/border/..)
• Various data types for input boxes (int/float/string/alpha/..)
• Data type restrictions within a data type (min-value/max-value for an int for instance)
• To generate a list of validation errors and prompts after submitting
• Different submission requirements for different fields (mandatory/optional)

With that in mind, I started writing it in ASP Classic as a learning tool. I’ll post the Class as a file to download and some explanations of it shortly.