I noticed a previous post where the person asking the question didn't know were the reset switch is. My reset switch is located on the main thermostat top above the heating element. I hit the reset switch and the water is hot for about two to three days. I notice were someone mentioned changing the breaker, how can you be sure?

If the breaker on your electric water heater keeps tripping then you have most-likely bad heating element. It could be few other problems but this is what I would start with...