[javascript] How to advance to the next form input when the current input has a value?

If you have jQuery UI this little function allows basic tabbing

handlePseudoTab(direction) {
    if (!document.hasFocus() || !document.activeElement) {
        return;
    }
    const focusList = $(":focusable", $yourHTMLElement);
    const i = focusList.index(document.activeElement);
    if (i < 0) {
        focusList[0].focus(); // nothing is focussed so go to list item 0
    } else if (direction === 'next' && i + 1 < focusList.length) {
        focusList[i + 1].focus(); // advance one
    } else if (direction === 'prev' && i - 1 > -1) {
        focusList[i - 1].focus(); // go back one
    }
}