Storage event handlers only fire if the storage event triggered by another window. You can try to run the following code:
// event handler window.addEventListener('storage', storageEventHandlerFunc, false); function storageEventHandlerFunc(evt) { alert("Storage event called key: " + event.key ); switch(event.key){ case 'one': case 'two': batteryDCMeter(); break; case 'extPowerOn': rechargeBattery(); break; } } sessionStorage.setItem("someKey", "someValue");