code: function updateProgress(event) {
  	    var _this4 = this;
  
  	    if (!this.supported.ui || !is$1.event(event)) {
  	      return;
  	    }
  
  	    var value = 0;
  
  	    var setProgress = function setProgress(target, input) {
  	      var value = is$1.number(input) ? input : 0;
  	      var progress = is$1.element(target) ? target : _this4.elements.display.buffer; // Update value and label
  
  	      if (is$1.element(progress)) {
  	        progress.value = value; // Update text label inside
  
  	        var label = progress.getElementsByTagName('span')[0];
  
  	        if (is$1.element(label)) {
  	          label.childNodes[0].nodeValue = value;
  	        }
  	      }
  	    };
  
  	    if (event) {
  	      switch (event.type) {
  	        // Video playing
  	        case 'timeupdate':
  	        case 'seeking':
  	        case 'seeked':
  	          value = getPercentage(this.currentTime, this.duration); // Set seek range value only if it's a 'natural' time event
  
  	          if (event.type === 'timeupdate') {
  	            controls.setRange.call(this, this.elements.inputs.seek, value);
  	          }
  
  	          break;
  	        // Check buffer status
  
  	        case 'playing':
  	        case 'progress':
  	          setProgress(this.elements.display.buffer, this.buffered * 100);
  	          break;
  
  	        default:
  	          break;
  	      }
  	    }
  	  }
docs: Update <progress> elements