document.activeElement, it is supported in all major browsers.
Previously, if you were trying to find out what form field has focus, you could not. To emulate detection within older browsers, add a "focus" event handler to all fields and record the last-focused field in a variable. Add a "blur" handler to clear the variable upon a blur event for the last-focused field.
If you need to remove the
activeElement you can use blur;
document.activeElement.blur(). It will change the