I'm adding a 'speaking' class to show a border when the user is speaking. When I speaking, the code working:

 if (options.uid == volume.uid && volume.level > volumeLevel) {
    document.getElementById(options.uid).classList.add("speaking");
  }else if (options.uid == volume.uid && volume.level < volumeLevel) {
    document.getElementById(options.uid).classList.remove("speaking");
  }

But other users in other pages, get a error: TypeError: Cannot read property 'classList' of null

if(options.uid != volume.uid && volume.level > volumeLevel) {
   document.getElementById(options.uid).classList.add("speaking");
 }else if (options.uid != volume.uid && volume.level < volumeLevel) {
   document.getElementById(options.uid).classList.remove("speaking");
 }

Full code

var volumeLevel=15; 
  rtc.on("volume-indicator", volumes => {
    volumes.forEach((volume) => {
      if (options.uid == volume.uid && volume.level > volumeLevel) {
        document.getElementById(options.uid).classList.add("speaking");
      }else if (options.uid == volume.uid && volume.level < volumeLevel) {
        document.getElementById(options.uid).classList.remove("speaking");
      }
      if (options.uid != volume.uid && volume.level > volumeLevel) {
        document.getElementById(options.uid).classList.add("speaking");
      }else if (options.uid != volume.uid && volume.level < volumeLevel) {
        document.getElementById(options.uid).classList.remove("speaking");
      }
    });
  })