Minimim characters in a text box

Question

It seems silly that it is so easy to set the maximum number of characters in a text box (ie. Properties>Options>Limit of X characters) but that there is no easy equaivalent for minimum characters? At least not in Acrobat 9 anyway, don't know about the never versions!
Does anyone know if the minimum number of characters can be set with Javascript?

Answer 1

That was intended to be a rhetorical question. So what you really want is if the field is not blank, that there should at least be some minimum number of characters. What is the minimum number that you want to enforce? Youd probably want to use a custom validation script for this, but what exactly do you want to happen if the user only enters three characters but the minimum you want is four? Should the three characters that were entered be rejected altogether, or should the focus just be set back to the field so the user can enter more, or something else?
Here's what a script that rejects the entry might look like:
// Custom validate script for text field
(function () {
    // Allow nothing
    if (!event.value) return;
    // Set the minimum number of characters
    var min_chars = 4;
    // Reject the entry and alert user if fewer than the minimum
    if (event.value.length < min_chars) {
        event.rc = false;
        app.alert("Please enter at least " + min_chars + "characters.\r\rYou entered " + event.value.length + " characters.", 1);