how do i change fore color in a textbox with javascript

@sqlchopper asked for negative numbers to appear in red; @tgreer was right that the element's CSS color should be changed rather than a non‑existent forecolor property. A cleaner, more robust pattern is to let CSS handle presentation and have JavaScript decide the state (negative/positive/invalid) by toggling semantic classes. That avoids inline styling, handles decimals/commas, and makes maintenance easier.

/* keep colors in CSS */
input.negative { color: #c00; }
input.positive { color: #000; }

// attach an input handler that toggles classes
(function(){
  const el = document.querySelector('#nm1TextBox');
  if (!el) return;
  const update = () => {
    const raw = el.value.trim();
    const num = raw === '' ? NaN : Number(raw.replace(/,/g, ''));
    if (!isFinite(num)) {
      el.classList.remove('negative','positive');
      return;
    }
    el.classList.toggle('negative', num < 0);
    el.classList.toggle('positive', num >= 0);
  };
  el.addEventListener('input', update);
  update();
})();

Notes and troubleshooting: use Number() or parseFloat() for decimals (if parseInt() is used, pass a radix like parseInt(x,10)), strip thousands separators before parsing, and ensure the field exists before attaching handlers. Placeholder text and disabled inputs may be styled differently by the browser, so test those states. For accessibility, don't rely on color alone — keep the minus sign or add an explicit label/aria text for screen readers. If input masking or locale-aware formatting is needed, prefer an established small library (or input type="number" with careful validation) rather than ad‑hoc string hacks.