test.js

window.onload = function () {
    // attach keyDown event
    document.addEventListener("keydown", keyDownHandler, false);
};

function keyDownHandler(e) {
    var keyCode = e.keyCode;

    // set fields to editable
    TXTextControl.textFieldsEditable = true;

    // if DELETE or BACKSPACE
    if (keyCode == 8 || keyCode == 46) {
        TXTextControl.getTextFields(function (e) { // get field at input positions
            if (typeof e !== 'undefined' && e.length > 0) { // if array is defined
                // remove the field at the input position
                TXTextControl.removeTextField(e[0], false);
            }
        }, true);
    }
}