Check Input hook

Use this hook to validate a custom field. You can use the values of the standard form fields and other custom fields.

Example:

function extern void ext.currency.check.input()
{
        if txcomdll0001.is.currency.blocked.for.printing(ext.currency) then
                set.input.error("@" & 
                    sprint$("You cannot select currency %s; it is blocked",
                            ext.currency))
        endif
}