How to disable backspace if anything other than input field is focused on using jquery

Question

How do I disable backspace keystroke if anything other than 2 specific input fields are focused on using jquery?

here is my current code (NOW INCLUDING 2 TEXTBOXES):

Answer 1

I think this would do the trick:

$(document).keydown(function(e) {
    var elid = $(document.activeElement).hasClass('textInput');
    if (e.keyCode === 8 && !elid) {
        return false;
    };
});

assuming that the textboxes has the class 'textInput'.

Here is a working example