var oKeyListener = new Object();
oKeyListener.text_array = [text1_txt, text2_txt, text3_txt];
oKeyListener.oTextFields = new Object();
for (var i = 0; i<oKeyListener.text_array.length; ++i) {
    // oKeyListener.text_array[i].tabEnabled = true;
    oKeyListener.text_array[i].tabIndex = i;
    oKeyListener.oTextFields[oKeyListener.text_array[i]] = i;
}
oKeyListener.onKeyDown = function() {
    if (Key.getCode() == Key.ENTER) {
        var selected_txt = eval(Selection.getFocus());
        var nID = this.oTextFields[selected_txt];
        if (nID>=0) {
            var next_txt = this.text_array[++nID%this.text_array.length];
            Selection.setFocus(String(next_txt));
        }
    }
};
Key.addListener(oKeyListener);