hi guys - once again another problem with my nissan

It was snowing here this afternoon and I was running out of windshield washer fluid - and I was in a rush, I started pouring the stuff and managed to overfill the resevoir getting some fluid down the side (not much at all)

anyway i got in and drove down the road and after baout 15 minutes the BATTERY LIGHT AND THE BRAKE light came on and stayed on. I drove around - and let the car even idle for 10 minutes and drove home - about 20 minutes without any problem?

Is my alternator done for? or is it just from some fluid getting in therE?



Thanks

Sunny