gistfile1.js

	var toggleGainState = function(elementId, elementClass, outputElement){
		var ele = document.getElementById(elementId);
		return function(){
			if (outputElement.gain.value === 0) {
				outputElement.gain.value = 1;
				ele.classList.remove(elementClass);
			} else {
				outputElement.gain.value = 0;
				ele.classList.add(elementClass);
			}
		};
	};

	var toggleSpeakerMute = toggleGainState('speakerMute', ‘button--selected', outputGain);
	var toggleMicMute = toggleGainState('micMute', ‘button--selected', micGain);