After further testing, it appears that .removeAttr('maxLength') works in both IE7 and Ffx 3.0.6. Still not correct behavior, but it solves my immediate issue.

to clarify, 'maxLength' works, 'maxlength' does not.

Can you clarify what the original problem was? Were you trying to "clear" maxlength so that the field wasn't constrained?

NB: There is actually a

.maxLength

*property* on input elements; IE and Firefox do not treat the "no max length" the same way. I seem to recall that IE uses -1 and FF uses 2^31.

Perhaps I am using it in the wrong way, then. My initial frustration was with removing the maxlength from a text input, to instead color the field when the maximum length was exceeded - as part of an unobtrusive form validation script.

<input type='text' id='target' maxlength='3'>

The above limits the field to 3 characters - no more may be entered. Now if we execute this:

$('input#target').removeAttr('maxlength');

The limitation is removed in Firefox (so the field now has no maximum length), but it is changed to 0 in IE7, so you cannot input any characters at all. If I use this instead (notice capitalization):

$('input#target').removeAttr('maxLength');

it works properly in all three major browsers.

Hmmm, maybe adding maxlength to jQuery.props would fix this?

Fixed in 1.4a1; maxLength is in jQuery.props.

This (still? again?) seems to be a problem: http://jsfiddle.net/dcrQg/